Organic Structures From Spectra-Edition 4-Solutions Manual-libre

Please Keep Absolutely Confidential

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

Solutions Manual

December 2007

1

Please Keep Absolutely Confidential

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman 5

1

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

9

BrCH2 CH2Br

O

13

OH OH CH3

C

C

Cl2CH CH3

CH3

CH3 CH3

2

2-butanone

1,2-dibromoethane

pinacol

1,1-dichloroethane

C4H8O

C2H4Br2

C6H14O2

C2H4Cl2

CH3CH2

OH

6

10

O CH3

O

O

O

14

CH3 H

CH3

CH3 OH

O

propionic acid

1,2-butanedione (biacetyl) C4H6O2

C3H6O2

3

O CH2CH3 CH3

4

7

O

CH2C

N

CH2C

N

11

1,4-cyclohexanedione

2-propanol

C6H8O2

C3H8O

O

15

CH3 H

CH3 Br

ethyl acetate

succinonitrile

cyclopentanone

2-bromopropane

C4H8O2

C4H4N2

C5H8O2

C3H7Br

CH3O

CH2CH3 O

8

12

CH3 CH3 CH3 C

C

CH3CH2 I

16

Cl

Cl

CH3

CH3 CH3

December 2007

methyl propionate

2,2,3,3-tetramethylbutane

iodoethane

1,4-dichlorobutane

C4H8O2

C8H18

C2H5I

C4H8Cl2

2

Please Keep Absolutely Confidential

17

Br

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman 21

Br

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

H2N

25

COOH

N

CH2C

29

CH2 C CH3 O

1,3-dibromopropane

4-aminobutyric acid

benzyl cyanide

benzyl methyl ketone

C3H6Br2

C4H9NO2

C8H7N

C9H10O

18

Br

22

Cl

26

OCH3

CH2NH2

30

O

1-bromo-3-chloropropane

anisole

benzylamine

propiophenone

C3H6BrCl

C7H8O

C7H9N

C9H10O

19

Br

N

C

23

27

CH2OH

OH

31

CH3 CH C H O

4-bromobutyronitrile

benzyl alcohol

2-phenylethanol

2-phenylpropionaldehyde

C4H6NBr

C7H8O

C8H10O

C9H10O

28 + NH3

20 CH3

December 2007

H

COO

24

OH

CH2Br

32

O

H CH3

-

alanine

benzyl bromide

1-phenylethanol

butyrophenone

C3H7NO2

C7H7Br

C8H10O

C10H12O

3

Please Keep Absolutely Confidential

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman O

33

O O

34

37

O

41

N

CH3

O

C

O

45

C

O

CH3

O

CH3

H CH3 O

O

H

t-butyl acetoacetate

dibenzylamine

propionic anhydride

1,1-diacetoxyethane

C8H14O3

C14H15N

C6H10O3

C6H10O4

CH3CH2 O C H

38

42

CH3

O

CH3

N

N

ethyl formate

CH3

O

35

O

39

C

H

O

COOCH3 CH3

diethyl oxalate

dimethyl methylmalonate

C6H10O4

C6H10O4

43

O

47

O CH3

O

O

O CH3

CH3

CH3 O

O

O

O

C

CH3OOC

O

N,N,N,N-tetramethyl-1,2ethanediamine C6H16N2

C3H6O2

46

O

CH3

C O

OCH3

benzil

2,5-hexanedione

ethylene glycol diacetate

methyl acetyllactate

C14H10O2

C6H10O2

C6H10O4

C6H10O4

36

40

44

O CH3CH2O

OCH2CH3

48

O CH3O

OCH3 O

December 2007

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

O O

C

C

O

O

1,2-diphenylethane

diethyl carbonate

dimethyl succinate

diethyl succinate

C14H14

C5H10O3

C6H10O4

C8H14O4

4

Please Keep Absolutely Confidential

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman

O

49

53

O

O

57

CHCl2

O

H3C

CH3

H3C

CH3

61

OCH3 OCH3 OCH3

ethylene glycol dipropionate

α,α-dichlorotoluene

1,2,3-trimethoxybenzene

durene

C8H14O4

C7H6Cl2

C9H12O3

C10H14

CH3

50

51

O

O

C

C

O

54

58

OCH3 C

H OCH3

CH3

62

CH3

CH3

CH3

CH3

butyric anhydride

benzaldehyde dimethylacetal

mesitylene

1,2,3,4-tetramethylbenzene

C8H14O3

C9H12O2

C9H12

C10H14

Br

55

Br

59

OH

63

CH3

COOH

CH3

CH3 CH3

CH3

CH3

52

CH3

CH3

1,4-dibromobenzene

benzilic acid

1,2,3-trimethylbenzene

1,2,3,5-tetramethylbenzene

C6H4Br2

C14H12O3

C9H12

C10H14

Br

Br

56

60

OH

CH3 CH3

OH

CH3

64

CH3

CH3

CH3

CH3

CH3

CH3

4,4'-dibromobiphenyl

catechol

1,2,4-trimethylbenzene

hexamethylbenzene

C12H8Br2

C6H6O2

C9H12

C12H18

December 2007

5

Please Keep Absolutely Confidential

65

CH3

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman 69

CH3 CH3

1,2,3,4,5,pentamethylcyclopentadiene C10H16

66

CH3

CH3

3-hydroxybutanone (acetoin) C4H8O2

70

NH2

74

4-hydroxy-4-methyl-2pentanone C6H12O2

C2H5NO

71

O O

3,3-dimethylglutaric acid C7H12O4

78

HOOC

COOH

O

hexylamine

2,2-dimethylpentanedioc acid C7H12O4

C6H15N

75

CH3

79

O CH3CH2

O

CH3 CH3

CH3

O

CH3

Br

N

N CH3 O

ethyl glycolate

isobutyl acetate

ethyl 2-bromopropionate

tetramethylurea

C4H8O3

C6H12O2

C5H9O2Br

C5H12N2O

68

72

O CH3CH2O

December 2007

NH2

HOOC COOH CH3 CH3

O

acetamide

HO

CH3 CH3

2-methyl-2-butanol (t-amyl alcohol) C5H12O

HO

O

67

77

OH CH3

O

CH3

H

73

OH CH3

CH3

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

C

N

76

COOH

OCH3 O

80

O

O

OCH3

ethyl cyanoacetate

3,3-dimethylbutyric acid

4,4-dimethoxy-2-butanone

1,3-dioxan

C5H7NO2

C6H12O2

C6H12O3

C4H8O2

6

Please Keep Absolutely Confidential

81

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman 85

O

89

Br OH

O

93

CH2

HO

O

H

O

1,4-dioxan

2-bromohexanoic acid

2-methylbut-3-en-2-ol

dibutyl ether

C4H8O2

C6H11O2Br

C5H10O

C8H18O

82

O

86

O

O

90

CN

H

+ -

C H OH O

O

94

NH3

CH3

CN

O O

83

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

O

18-crown-6

2-ethylmalononitrile

threonine

butylbenzene

C12H24O6

C5H6N2

C4H9NO3

C10H14

H2C C

87

CH2Cl

91

CN

Br

95

C(CH3)3

Cl

2,3-dichloropropene

3-methylbutyronitrile

1-bromo-3-phenylpropane

t-butylbenzene

C3H4Cl2

C5H9N

C9H11Br

C10H14

84

88

O Cl

O

H2N

C

C

92

H

NO2

96

CH3

4-chlorobutyl acetate

5-amino-1-pentyne

1-nitropropane

sec-butylbenzene

C6H11O2Cl

C5H9N

C3H7NO2

C10H14

December 2007

7

Please Keep Absolutely Confidential

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman 101

97

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

Cl

C(CH3)3

105

O C

109

O CH3O

C

CH3

HO

CH2OCH3

CH3

neopentylbenzene

p-chloroacetophenone

4-methoxyacetophenone

4-methoxymethylphenol

C11H16

C8H7OCl

C9H10O2

C8H10O2

98

CH2Cl

102 CH3

O

106

O

CH3

C

C

O

110 CH3

CH3 N C

N CH3

Cl

4-(n-butyl)-α-chlorotoluene

p-toluyl chloride

p-cresyl acetate

4-dimethylaminobenzonitrile

C11H15Cl

C8H7OCl

C9H10O2

C9H10N2

99

103 O

CH3O

107

COOH

O H3C

111

CH3 Br

C

N CH3

OCH3

4-methyl-4-phenyl-2-pentanone C12H16O

100

O Br

C

104

p-anisic acid

methyl p-toluate

p-bromo-N,N-dimethylaniline

C8H8O3

C9H10O2

C8H10NBr

CH2O C

CH3

108

CH3O

CH2OH

O

CH3

112

O CH3O

C C(CH3)3

p-bromoacetophenone

benzyl acetate

p-methoxybenzyl alcohol

p-anisyl t-butyl ketone

C8H7OBr

C9H10O2

C8H10O2

C12H16O2

December 2007

8

Please Keep Absolutely Confidential

113

O (H3C)3C

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman 117

121

O

O C CH3

CH3CH2O C

H

NH2

125

N

O

4-t-butylphenyl acetate

o-nitrobenzaldehyde

ethyl p-aminobenzoate

C12H16O2

C7H5NO3

C9H11NO2

(CH3)3C

C OCH3 O

118

H C

122

OCH3

CH3CH2O

C

O

NH2

p-ethoxybenzamide

C12H16O2

C8H8O2

C9H11NO2

NO2

119

p-ethoxyacetanilide (phenacetin) C10H13NO2 H

126 HO

N

C CH3 O

4-methoxybenzaldehyde

CH3O

O 2N

C

C

H

123

p-hydroxyacetanilide (paracetamol) C8H9NO2

127

O CH3

CH3

O

O

methyl 4-t-butylbenzoate

115

C

CH3CH2O

NO2

114

H

O C

NH C CH3

O

O

116

p-nitroanisole

4-nitrophenylacetylene

4-methylacetanilide

ethyl p-ethoxybenzoate

C7H7NO3

C8H5NO2

C8H9NO

C11H14O3

H C

NO2

120

124

O C

O

O

C H3C

OH

128

O CH3 C

NH2

O

OCH3

O

p-nitrobenzaldehyde

4-acetoxybenzoic acid

4-aminoacetophenone

C7H5NO3

C9H8O4

C8H9NO

December 2007

CH3O

9

methyl (p-methoxyphenyl)propionionate C11H14O3

Please Keep Absolutely Confidential

129

H

N

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman 133

137

O

O

O C

O

O

O C

141

H

O

O

CH3

C O

N-isopropylbenzylamine

hydroquinone dipropionate

C10H15N

C12H14O4

130

134

OCH3 O

C

CH3

methyl 2-methoxy-2phenylacetate C10H12O3

131

NCO

O

cyclopropyl methyl ketone C5H8O

142 CH3O

C

O

O

138

O

O

1,3-dihydroxyphenyl dipropionate C12H14O4

C

C

H

OCH3

OH

C

O O

O

diethyl terephthalate

dimethyl o-phthalate

cyclopropane carboxylic acid

C12H14O4

C10H10O4

C4H6O2

O

135

C C

139

O

O O

143

H C O

O

132

phenyl isocyanate

diethyl o-phthalate

cycloheptanone

benzoylcylopropane

C7H5NO

C12H14O4

C7H12O

C10H10O

OCH3

136

O

OCH3 H

O

C

140

O C

144

H

CH2 C

O

OCH2CH3

O

phenylacetaldehyde dimethyl acetal C10H14O2

December 2007

diethyl isophthalate

cycloheptatriene

ethyl cyclobutanecarboxylate

C12H14O4

C7H8

C7H12O2

10

Please Keep Absolutely Confidential

145

O

C(CH3)3

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman 149

153

157

CH3

(CH3)3C

O

OH

O

C O

NEt2

(CH3)3C

4-t-butylcyclohexanone

benzyl benzoate

N,N-diethyl-m-toluamide

3,5-di-t-butylphenol

C10H18O

C14H12O2

C12H17NO

C14H22O

146

150

H

O

CH3

154

158

Br

Br

N H3C

O

N-methylacetamide

H2N NH2

Br

(p-cresyl)methyl phenyl ketone C15H14O2

C3H7NO

147

OH

O

CH3

151

CH3

O

2-bromophenol

3,5-dibromocumene

C6H5OBr

C9H10Br2

155

159

O

Br

O C CH3

O COOH

148

1,4-diaminobutane

p-cresyl phenylacetate

C4H12N2

C15H14O2

H2N

NH2

152

Cl3C

COOH

acetylsalicylic acid (aspirin) C9H8O4

156

CCl3

160

NH2 Br

3-bromo-5-isopropylbenzoic acid C10H11O2Br

Br

O O

H

O

1,5-diaminopentane C5H14N2

December 2007

1,3-bis(trichloromethyl)benzene C8H4Cl6

11

2,6-dibromoaniline

piperonal

C6H5NBr2

C8H6O3

Please Keep Absolutely Confidential

161

162

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman 165

CH3 CH3

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

169

O

NO2

173

O

3-nitro-o-xylene

2-cyclohexene-1-one

indane

α-tetralone

C8H9NO2

C6H8O

C9H10

C10H10O

Cl

CH3

Cl

Cl

166

170

O

174

O

OH O

2,4,5-trichlorotoluene

2-hydroxycyclohex1-en-3-one C6H8O2

C7H5Cl3

163

Cl

NH2

Cl

Cl

167

171

O C CH3

3,3-dimethylindan-1-one

β-tetralone

C11H12O

C10H10O

175

O

H

164

2,4,5-trichloroaniline

1-acetyl-1-cylohexene

1-indanone

9-methylfluorene

C6H4NCl3

C8H12O

C9H8O

C14H12

CH3O I

OCH3 I

168

172

CH3 CH3

O

4,6-diiodo-1,3dimethoxybenzene C8H8O2I2

176

O O

CH3

December 2007

CH3

4-methylpent-3-en-2-one (mesityl oxide) C6H10O

12

2-indanone

fluorenone

C9H8O

C13H8O

Please Keep Absolutely Confidential

177

CH3

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman 181

CH3CH2

185

CH3

H

O CH3 O

O

CH3

O

CH3 CH3

183

N

CH3 HO

C

C

C

mevalonic lactone C6H10O3

December 2007

C C C CH2CH3 OH

H

187

C

C C

OH

CH3

COOH H CH3

3-methyl-1-phenylpent1-yn-3-ol C12H14O

C C CH3

2-hydroxy-3-methylbutyric acid C5H10O3

191

OH

CH2

CH CH2

OH

OH OH

1-phenyl-1,3-pentadiyne

glycerol

C11H8

C3H8O3

COOCH3

188

H

C

O

C3H6Br2

CH3

CH3 C

O

CH3

2,5-dimethyl-3-hexyne2,5-diol C8H14O2

184

OH

1,2-dibromopropane

190

CH3

CH3

CH3

CH3

O

2,2-dimethylglutaric anhydride C7H10O3 CH3

(Z)-1-methoxybut1-en-4-yne C5H6O

1,2,2,6,6-pentamethylpiperidine C10H21N

CH3

180

H

CH3

3,3-dimethylglutaric anhydride C7H10O3

O

CH2Br H

186

O

O

O

182

O

CH3

CH3

C

4-ethyl-4-methyl-2,6piperidinedione C8H13NO2

CH3

179

OCH3

Br

H

2,4,6-trimethyl1,3,5-trioxane C6H12O3

CH3

N

189

H

C

O

178

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

192

OH CH3

O H

C HC

H

(Z)-3-methylpent-2en-4-ynal C6H6O

C NH2

CH

methyl 4-amino-3,5diethynylbenzoate C12H9NO2

13

CH3 H

2-butanol C4H10O

Please Keep Absolutely Confidential

193

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman 197

O

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

S

201

O NH2

S

O

Cl

205

H

NH2 O

O

dibenzyl sulfoxide

p-aminobenzenesulfonamide C6H8N2O2S

C14H14OS

vinyl 2-chloroethyl ether

cinnamaldehyde

C4H7OCl

C9H8O

198 194

202

O

S

206

O

S

N

O

COOH

CH2OH

CH3

O

(E)-3-(phenylthio)acrylic acid C9H8O2S

195

N-(p-tolyl)succinimide

cinnamyl alcohol

C4H6O2S

C11H11NO2

C9H10O

199

O CH3

divinyl sulfone

S OCH2CH3

207

Cl

H

H

CH

C(CH3)3

O H

ethyl p-toluenesulfonate

allyl p-anisyl thioether

C9H12O3S O

phenylacetaldeyde ethylene glycol acetal C10H12O2

C10H12OS O

CH3

O CH2

CH3O

O

196

203

S

200

O

(E)-3-chloro-4,4-dimethyl-1phenyl-1-pentene C13H17Cl

O S

O

CH2CH2O 4

S CH3

204

S

CH(CH3)2

208

H H

O

O

CH3

Br

CH3

p-tolyl methyl sulfoxide C8H10OS

December 2007

tetraethylene glycol ditosylate C22H30O9S2

(E)-1-phenyl-4-methyl-1penten-3-one C12H14O

14

(Z)-β-bromostyrene C8H7Br

Please Keep Absolutely Confidential

209

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman 213

H NO2

Br

217

H Cl

C

H

Cl

OH

O

214

Cl

Cl

Cl

3-benzyloxy-1-propanol

211

215

COOH

CH3O

O

219

Br

CH3O

222

H

CH3

5,6-dimethoxy-2coumaranone C10H10O4

December 2007

Cl

OCH2CH3

2-chloroacetaldehyde diethylacetal C6H13O2Cl

223

H

OCH3

C

H

CH2 O CH2

methyl (E)-3-methylacrylate

1,3-dibenzylglycerol

C5H8O2

C17H20O3

220

CH3

O CH2

CH2 HO

OCH3 O

224

O CH3O

OCH2CH3

CN

H

methyl 2,3-dibromo-3(p-nitrophenyl)propionate C10H9NO4Br2

216

malonaldehyde dimethyl acetal C7H16O4

4-cyano-2,2dimethylbutyraldehyde C7H11NO

O

C9H8O4

OCH2CH3

O

Br

212

218

COOH

COOH

homophthallic acid

OCH3 OCH3

diethyl isopropylidenemalonate C10H16O4

O

O2N

OCH3

O

2,4,5-trichlorophenoxyacetic acid (2,4,5-T) C8H5O3Cl3

C10H14O2

CH3O

OCH2CH3

CH3

1,1-di-(p-chlorophenyl)-2,2,2trichloroethane (DDT) C14H9Cl5

C8H6BrNO2

221

O CH3

CCl3

(E)-p-nitro-β-bromostyrene

210

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

N CN

OCH3

2,3-di-(p-anisyl)butyronitrile

2,5-dimethyl-2,4-hexadiene

pyridine

C18H19NO2

C8H14

C5H5N

15

Please Keep Absolutely Confidential

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman O

225

N

H3C

229

233

O

CH3

C

237

C

O2N

O

O

C H

CH(CH3)2

N

C

CH(CH3)2

S O

C O

4-picoline

isopropyl nicotinate

citraconic anhydride

C6H7N

C9H11NO2

C5H4O3

226

CH3

230

N

227

234 CH3

N

238 COOH

O

NH2

H

CH3

N N

2-picoline

2-methyl-6-aminopyridine

2-furoic acid

4-methylimidazole

C6H7N

C6H8N2

C5H4O3

C4H6N2

231

CH3

235

N N

H3C

C(CH3)3

O

N

239 S

O

3-picoline

4-methylpyrimidine

2-furyl t-butyl ketone

benzothiophene

C6H7N

C5H6N2

C9H12O2

C8H6S

228

232

O C

236

H O

CH3

240

O2N S

NO2

N

December 2007

2-(5-nitrothienyl) isopropyl ketone C8H9NO3S

N H

3-acetylpyridine

styrene epoxide

2,4-dinitrothiophene

2,3,4,9-tetrahydrocarbazole

C7H7NO

C8H8O

C4H2N2O4S

C12H13N

16

Please Keep Absolutely Confidential

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman 245

241 CH3

249

O

O

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

O

N CH3

α-angelicalactone

octahydroanthracene

N-methylmorpholine

C5H6O2

C14H18

C5H11NO

253

OH HO

N(CH3)2

N,N-dimethyl-2,3-dihydroxy1-propylamine C5H13NO2

O O

242

246

250

H CH3

O

N CH3

anthraquinone

cyclopentanone oxime

pseudoephedrine

C14H8O2

C5H9NO

C10H15NO

247

251

OH

255

N

H O

N C(CH3)3

H

butyrolactone

dodecahydrotriphenylene

cyclohexanone oxime

t-butylformamide

C4H6O2

C18H24

C6H11NO

C5H11NO

244

248

O

252

CH3

CH3 CH3 O

O

256

H HS CH2 CH

N H

CH3

tetramethyl-1,3cyclobutanedione C8H12O2

December 2007

H

CH3

OH

O

O

254

O

2-methyltetrahydrofuran-3-one C5H8O2

243

OH N

N

COOH

C O

triphenylene

ε-caprolactam

N-acetylcysteine

C18H12

C6H11NO

C5H9NO3S

17

CH3

Please Keep Absolutely Confidential

257

HO HO

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman 261

OH

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

265

O H

CH CH2NH CH3

269

OH CH3

CH3

O HO

H OH

CH3

H

C

O OH CH3

N H O

adrenalin

3-methylbutyraldehyde

2-methyl-2,4-pentanediol

N-acetylglutamic acid

C9H13NO3

C5H10O

C6H14O2

C7H11NO5

258 N H

CH2 CH COO+ NH3

262

266

OCH2CH3 CH2 CH

270

OCH3

H

O

CH OH

OCH2CH3

HO

OCH2CH3 CH3

N H O

tryptophan

acrolein diethyl acetal

eugenol

N-acetyltyrosine ethyl ester

C11H12N2O2

C7H14O2

C10H12O2

C13H17NO4

259

263

H N

S

O

C

C

H

271 O

C (CH3)3C

O

HO C CH2CH2 CH COOH O NH2

C

C

CH3

N-acetylhomocysteine thiolactone C6H9NO2S

260

Cl

H

267

NH2

allylamine

E -1-chloro-4-(4-tbutylphenyl)but-1-en-3-yne C14H15Cl

C3H7N

264

268

H

HO O

OH CH3

N

C4H6O

272

O

H

2,5-dihydrofuran

O

O

December 2007

glutamic acid

adamantine

N-acetylaspartic acid

2,3-dihydrofuran

C5H9NO4

C10H16

C6H9NO5

C4H6O

18

Please Keep Absolutely Confidential

273

COOH

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman 277

281

Cl

O O

N C

COOH

O CH2CH3

2,3-naphthalenedicarboxylic acid C12H8O4

274

OCH3

2-chloronaphthalene

ethyl 4-piperidone-Ncarboxylate C8H13NO3

C10H7Cl

278

282

COOH CH3 N C O H

NO2

1-methoxy-4-nitronaphthalene C11H9NO3 CH3

275

sec-butylbenzene

N-acetyl-2-amino-4-phenyl(E)-but-2-enoic acid C12H13NO3

C10H14

279

283

CH3 O

CH3O

O

N H

CH3

CH3

OCH3

1,5-dimethylnaphthalene

N-(1-methyl-1-phenylethyl)butyramide C12H17NO

C12H12

276

280

CH3

O OCH2CH3

CH3

1,3-dimethylnaphthalene C12H12

December 2007

OCH2CH3 O

diethyl 2-(1,1dimethylheptyl)malonate C16H30O4

19

OH

3-hydroxy-3-methyl-5,8dimethoxy-1-coumarinone C13H16O4

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

Please Keep Absolutely Confidential

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman

Chapter 9.2 – The Analysis of MixturesProblem 284

Problem 286

Problem 284 Compound

Mole %

ethanol

57

bromoethane

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

Compound

Mole %

benzene

24

ethyl acetate

59

dioxane

17

Compound

Mole %

ethanol

41

bromoethane

59

43

Problem 285

Compound

Mole %

benzene

15

diethyl ether

dichoromethane

December 2007

Problem 287

46

39

20

Please Keep Absolutely Confidential

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman

Problem 288

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

Problem 290 Compound

Mole %

Compound

Mole %

benzene

13

fluorene

75

diethyl ether

22

fluorenone

25

dichoromethane

65

Compound

Mole %

4-nitroanisole

38

2-nitroanisole

62

Problem 291 Problem 289

December 2007

Compound

Mole %

benzene

23

ethyl acetate

51

dioxane

26

21

Please Keep Absolutely Confidential

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman Problem 294

Chapter 9.3 – Problems in 2D NMR Problem 292 Proton H1 H2 H3 H4

1-propanol

Chemical Shift (δ) in ppm 3.49 1.50 0.85 2.95

Problem 293

December 2007

Carbon C1 C2 C3

Chemical Shift (δ) in ppm 64.0 25.5 9.9

1-iodobutane

22

isobutanol

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

Please Keep Absolutely Confidential

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman

Problem 295

Problem 297 1

3-heptanone

CH3

2

3

4

5

CH2

C

CH2

CH2

6

CH2

4

7

1-bromobutane

CH3

3

CH3

2

CH2

1

CH2

CH2

Br

O

Proton

Chemical Shift (δ) in ppm

H1

0.91

H2

1.94

H4

1.97

H5

1.44

H6

1.14

H7

0.79

Carbon

H1

Chemical Shift (δ) in ppm 3.39

C1

Chemical Shift (δ) in ppm 33.4

H2

1.82

C2

34.7

H3

1.45

C3

21.4

H4

0.91

C4

13.2

Proton

Problem 298 1

3-octanone

2

CH3

CH2

δ-valerolactone

Proton

2

4 5

Chemical Shift (δ) in ppm

Proton

O

Carbon C1

Chemical Shift (δ) in ppm 170.0

H2

2.08

C2

29.9

H3

1.16

C3

22.2

H4

1.08

C4

19.0

H5

3.71

C5

68.8

December 2007

5

CH2

CH2

6

CH2

7

CH2

8

CH3

Carbon

H1

Chemical Shift (δ) in ppm 0.92

C1

Chemical Shift (δ) in ppm 7.8

H2

1.92

C2

35.4

C3

209.0

1

O

C

4

O

3

Problem 296

3

23

H4

1.94

C4

42.1

H5

1.47

C5

23.7

H6

1.11

C6

31.7

H7

1.19

C7

22.7

H8

0.82

C8

14.0

Please Keep Absolutely Confidential

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman

Problem 299

Problem 300 c

b

a

a

COOCH2CH3 d

diethyl diethylmalonate

e

f

g

CH3CH2 C

butyl ethyl ether

h

CH2

c

O

d

e

f

CH2 CH2 CH2 CH3

Ha

Chemical Shift (δ) in ppm 1.11

Hb

3.29

Cb

66.0

Hc

3.27

Cc

70.1

Ca

Chemical Shift (δ) in ppm 14.0

Hd

1.52

Cd

32.1

Cb

60.8

He

1.36

Ce

19.4

Cc

171.9

Hf

0.87

Cf

13.5

i

Carbon

Ha

Chemical Shift (δ) in ppm 1.19

Hb

4.13

Proton

j

k

Hd

0.76

Cd

8.1

He

1.88

Ce

24.5

Cf

58.0

Hg

1.88

Cg

24.5

Hh

0.76

Ch

8.1

Ci

171.9

Hj

4.13

Cj

60.8

Hk

1.19

Ck

14.0

December 2007

CH3

b

CH2CH3

COOCH2CH3

Proton

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

24

Carbon

Ca

Chemical Shift (δ) in ppm 15.0

Please Keep Absolutely Confidential

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman

Problem 301

Problem 302

1-iodobutane

butyl butyrate

Carbon

Ha

Chemical Shift (δ) in ppm 0.75

Ca

Chemical Shift (δ) in ppm 13.9

Hb

1.19

Cb

19.5

Hc

1.40

Cc

31.2

Hd

3.97

Cd

64.0

Ce

172.8

Proton

Hf

2.08

Cf

36.2

Hg

1.52

Cg

19.0

Hh

0.79

Ch

13.9

December 2007

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

1-butanol

1-iodobutane

25

1

4

3

2

1

CH3

CH2

CH2

CH2

4

3

2

1

CH3

CH2

CH2

CH2 OH

I

1

1-butanol

H1

H Chemical Shift (δ) in ppm 2.70

H1

H Chemical Shift (δ) in ppm 3.41

H2

1.40

H2

1.27

H3

1.08

H3

1.39

H4

0.64

H4

0.84

-OH

1.95

Please Keep Absolutely Confidential

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman

Problem 303

Problem 304 CH3

(E)- and (Z)-2-butene

H C

(Z)-3-methyl-2-penten-4-ynol

C CH2OH

C C H

H

Problem 305

Br C

C CH3

CH3

H8

NO2

H7

H2

H6

H3

1-nitronaphthalene H5

H

CH3 C

CH3

December 2007

C Br

26

H4

Proton

Chemical Shift (δ) in ppm

H2

8.22

H3

7.53

H4

8.10

H5

7.95

H6

7.62

H7

7.71

H8

8.56

Please Keep Absolutely Confidential

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman

Problem 306

Problem 309 COOCH2CH3

ethyl diethylmalonate

CH3

CH3CH2 C

geraniol

COOCH2CH3

H CH3 HOCH2

Problem 307

butyl valerate

CH3 CH2 CH2 CH2

O

C

CH2

CH2

CH2

CH3

O

Problem 308 CH3

nerol

CH3

H CH3 H

December 2007

CH3

H

CH2OH

27

H

Please Keep Absolutely Confidential

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

Chapter 9.4 – Analysis of NMR Spectra Problem 310

Problem 311

Structure

Number of 1H environments

Number of 13C environments

CO CH2CH2CH3

4

5

CH3CH2 CO CH2CH3

2

3

CH2 CHCH2CH3

5

4

cis- CH3CH CHCH3

2

2

trans-CH3CH CHCH3

2

2

1

1

3

4

2

3

3

4

1

2

2

4

5

7

slow chairchair

2

1

fast chairchair

1

1

rigid

7

CH3

Cl Br

Chemical Shifts

δA = 300 Hz / 60 MHz = 5.0 ppm δM = 240 Hz / 60 MHz = 4.0 ppm δX = 120 Hz / 60 MHz = 2.0 ppm

Br Cl

Cl

Br

Br

Br

Cl

Cl

OCH3

H

Problem 312

Chemical Shifts 4

Cl

December 2007

28

δA = 180 Hz / 200 MHz = 0.90 ppm δM = 220 Hz / 200 MHz = 1.22 ppm δX = 300 Hz / 200 MHz = 1.50 ppm

Please Keep Absolutely Confidential

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman

Problem 313

Problem 314 Spin System

Chemical Shifts

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

A2X3

δA = 150 Hz / 400 MHz = 0.375 ppm δX = 300 Hz / 400 MHz = 0.750 ppm

Chemical Shifts

1st Order Analysis

δA = 3.36 ppm = 3.36 x 60 = 202 Hz from TMS δX = 1.11 ppm = 1.11 x 60 = 67 Hz from TMS ΔνAX = νA - νX = 202 - 67 = 135 Hz ΔνAX / JAX = 135 / 7 = 19.3

This ratio is much greater than 3 so a 1st order analysis is justified.

December 2007

29

Please Keep Absolutely Confidential

Problem 315

Spin System

Chemical Shifts

Coupling constants

1st Order Analysis

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman AMX

Problem 316

δA = 501 Hz / 100 MHz = 5.01 ppm δM = 439 Hz / 100 MHz = 4.39 ppm δX = 408 Hz / 100 MHz = 4.08 ppm

Spin System

Chemical Shifts

JAM = 3.1 Hz JAX = 20.1 Hz JMX = 1.1 Hz

Coupling constants

ΔνΑΜ = νA - νM = 501 - 439 = 62 Hz ΔνΑΞ = νA - νX = 501 - 408 = 93 Hz ΔνΜΞ = νM - νX = 439 - 408 = 31Hz ΔνΑΜ / JAM = 62 / 3.1 = 20.0 ΔνΑΞ / JAX = 93 / 20.1 = 4.6 ΔνΜΞ / JMX = 31 / 2.1 = 14.7

1st Order Analysis

All ratios are greater than 3 so a 1st order analysis is justified.

AMX

δA = 460 Hz / 60 MHz = 7.67 ppm δX = 442 Hz / 60 MHz = 7.37 ppm δM = 394 Hz / 60 MHz = 6.57ppm JAM = 1.70 Hz JAX = 0.85 Hz JMX = 3.65 Hz

ΔνΑΜ = νA - νM = 460 - 394 = 66 Hz ΔνΑΞ = νA - νX = 460 - 442 = 18 Hz ΔνΜΞ = νM - νX = 442 - 394 = 48 Hz ΔνΑΜ / JAM = 66 / 1.7 = 38.8 ΔνΑΞ / JAX = 18 / 0.85 = 21.2 ΔνΜΞ / JMX = 48 / 3.65 = 13.2

All ratios are greater than 3 so a 1st order analysis is justified.

December 2007

30

Please Keep Absolutely Confidential

Problem 317

Spin System

Chemical Shifts

Coupling constants

1st Order Analysis

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman

AMX

Problem 318

Spin System

δ3 = 673 Hz / 100 MHz = 6.73 ppm δ4 = 719 Hz / 100 MHz = 7.19 ppm δ6 = 777 Hz / 100 MHz = 7.77ppm Chemical Shifts

3

J34 = 8.8 Hz J46 = 2.3 Hz 5 J36 not resolved (< 1Hz)

4

Δν34 = ν4 - ν3 = 719 - 673 = 46 Hz Δν46 = ν6 - ν4 = 777 - 719 = 58 Hz Δν36 = ν6 - ν3 = 777 - 673 = 104 Hz Δν34 / J34 = 46 / 8.8 = 5.2 Δν46 / J46 = 58 / 2.3 = 25.2 Δν36 / J36 = 104 / 104

Coupling constants 1st Order Analysis

All ratios are greater than 3 so a 1st order analysis is justified.

December 2007

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

AMX

δA = 628 Hz / 100 MHz = 6.28 ppm δB = 527 Hz / 100 MHz = 5.27 ppm δC = 592 Hz / 100 MHz = 5.92 ppm JAB = 2.1 Hz; JAC = 17.5 Hz; JBC = 9.9 Hz ΔνAB = νA - νB = 628 - 527 = 101 Hz ΔνAC = νA - νC = 628 - 592 = 36 Hz ΔνBC = νC - νB = 592 - 527 = 65 Hz ΔνAB / JAB = 101 / 2.1 = 48.1 ΔνAC / JAC = 36 / 17.5 = 2.1 ΔνBC / JBC = 65 / 9.9 = 6.6

2 out of 3 ratios are greater than 3 so this is borderline 1st order. The main deviation from 1st order is that intensities are severely distorted - a 1st order spectrum would have all lines of equal intensity. JAC = 17.5 Hz indicates that HA and HC must be trans. JBC = 9.9 Hz indicates HA and HC are cis. 31

Please Keep Absolutely Confidential

Problem 319

Spin System

Chemical Shifts

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman AX3

Problem 320

Spin System

AX3

δA = 160 Hz / 60 MHz = 2.67 ppm δX = 280 Hz / 60 MHz = 4.67 ppm

Chemical Shifts

δA = 199 Hz / 100 MHz = 1.99 ppm δX = 99 Hz / 100 MHz = 0.99 ppm

Coupling constants

JAX = 5 Hz

1st Order Analysis

ΔνAX = νA - νX = 199 - 99 = 100 Hz ΔνAX / JAX = 100 / 5 = 20.0

ΔνAX / JAX is much greater than 3 so a 1st order analysis is justified.

December 2007

32

Please Keep Absolutely Confidential

Problem 321

4 Spin System AMX2

Chemical Shifts

December 2007

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman Problem 322

δA = 340 Hz / 60 MHz = 5.67 ppm δM = 240 Hz / 60 MHz = 4.00 ppm δX = 100 Hz / 60 MHz = 1.67 ppm

4 Spin System AM2X

Chemical Shifts

33

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

δA = 110 Hz / 60 MHz = 1.83ppm δM = 200 Hz / 60 MHz = 3.33 ppm δX = 290 Hz / 60 MHz = 4.83 ppm

Please Keep Absolutely Confidential

Problem 323 4 Spin System

Chemical Shifts

Coupling constants 1st Order Analysis

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman AM2X

Problem 324 4 Spin System

δA = 646 Hz / 100 MHz = 6.46 ppm δM = 510 Hz / 100 MHz = 5.10 ppm δX = 395 Hz / 100 MHz = 3.95 ppm

Chemical Shifts

JAM = 3 Hz; JAX = 16 Hz; JMX = 5 Hz;

ΔνAX = νA - νX = 646 - 395 = 251 Hz ΔνAM = νA - νM = 646 - 510 = 136 Hz ΔνMX = νM - νX = 510 - 395 = 115 Hz

Coupling constants 1st Order Analysis

ΔνAX / JAX = 251 / 16 = 15.7 ΔνAM / JAM = 136 / 3 = 45.3 ΔνMX / JMX = 115 / 5 = 23.0

A2MX

δA = 279 Hz / 100 MHz = 2.79 ppm δM = 149 Hz / 100 MHz = 1.49 ppm δX = 39 Hz / 100 MHz = 0.39 ppm JAM = 4.5 Hz; JAX = 7.5 Hz; JMX = 11.0 Hz; ΔνAX = νA - νX = 279 - 39 = 240 Hz ΔνAM = νA - νM = 279 - 149 = 130 Hz ΔνMX = νM - νX = 149 - 39 = 110 Hz

ΔνAX / JAX = 240 / 7.5 = 32.0 ΔνAM / JAM = 130 / 4.5 = 28.9 ΔνMX / JMX = 110 / 11 = 10.0

All ratios are significantly greater than 3 so a 1st order analysis is justified.

All ratios are significantly greater than 3 so a 1st order analysis is justified.

December 2007

34

Please Keep Absolutely Confidential

Problem 325 4 Spin System

Chemical Shifts

Coupling constants 1st Order Analysis

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman AMX2

Problem 326 5 Spin System

δA = 302 Hz / 100 MHz = 3.02 ppm δM = 160 Hz / 100 MHz = 1.60 ppm δX = 37 Hz / 100 MHz = 0.37 ppm

Chemical Shifts

JAM = 12.0 Hz; JAX = 5.0 Hz; JMX = 8.0 Hz; ΔνAX = νA - νX = 302 - 37 = 265 Hz ΔνAM = νA - νM = 302 - 160 = 142 Hz ΔνMX = νM - νX = 160 - 37 = 123 Hz

Coupling constants 1st Order Analysis

ΔνAX / JAX = 265 / 5.0 = 53.0 ΔνAM / JAM = 142 / 12.0 = 11.8 ΔνMX / JMX = 123 / 8.0 = 15.4

A2M2X

δA = 1000 Hz / 200 MHz = 5.0 ppm δM = 500 Hz / 200 MHz = 2.5 ppm δX = 100 Hz / 200 MHz = 0.5 ppm JAM = 3.0 Hz; JAX = 7.0 Hz; JMX = 10.0 Hz; ΔνAX = νA - νX = 1000 - 100 = 900 Hz ΔνAM = νA - νM = 1000 - 500 = 500 Hz ΔνMX = νM - νX = 500 - 100 = 400 Hz

ΔνAX / JAX = 900 / 7.0 = 128.6 ΔνAM / JAM = 500 / 3.0 = 166.7 ΔνMX / JMX = 400 / 10.0 = 40.0

All ratios are significantly greater than 3 so a 1st order analysis is justified.

All ratios are significantly greater than 3 so a 1st order analysis is justified.

December 2007

35

Please Keep Absolutely Confidential

Problem 327 5 Spin System

Chemical Shifts

Coupling constants 1st Order Analysis

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman AMX3

δA = 710 Hz / 100 MHz = 7.10 ppm δM = 585 Hz / 100 MHz = 5.85 ppm δX = 192 Hz / 100 MHz = 1.92 ppm JAM = 15.3 Hz; JAX = 6.9 Hz; JMX = 1.6 Hz; ΔνAX = νA - νX = 710 - 192 = 518 Hz ΔνAM = νA - νM = 710 - 585 = 125 Hz ΔνMX = νM - νX = 585 - 192 = 393 Hz

ΔνAX / JAX = 518 / 6.9 = 84.7 ΔνAM / JAM = 125 / 15.3 = 8.2 ΔνMX / JMX = 393 / 1.6 = 245.6

All ratios are significantly greater than 3 so a 1st order analysis is justified. JAM = 15.3 Hz is typical of a coupling between vinylic protons which are trans to each other (see Section 5.7)

December 2007

36

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

Please Keep Absolutely Confidential

Problem 328 5 Spin System

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman ADMX3

1st Order Analysis

ΔνAD = νA ΔνAM = νA ΔνAX = νA ΔνDM = νD ΔνDX = νD ΔνMX = νM-

νD = 956 - 695 = 261 Hz νM = 956 - 619 = 337 Hz νX = 956 - 205 = 751 Hz νM = 695 - 619 = 76 Hz νX = 695 - 205 = 490 Hz νX = 619 - 205 = 414 Hz

ΔνAD / JAD = 261 / 261 ΔνAM / JAM = 337 / 8.2 = 41.1 ΔνAX / JAX = 751 / 751 ΔνDM / JDM = 76 / 15.8 = 4.8 ΔνDX / JDX = 490 / 6.9 = 71.0 ΔνMX / JMX = 414 / 1.6 = 258.8

All ratios are significantly greater than 3 so a 1st order analysis is justified. The critical coupling constant is JDM = 15.8 Hz which is typical of a coupling between vinylic protons which are trans to each other (see Section 5.7). The compound is: O H

Chemical Shifts

Coupling constants

December 2007

δA = 956 Hz / 100 MHz = 9.56 ppm; δD = 695 Hz / 100 MHz = 6.95 ppm; δM = 619 Hz / 100 MHz = 6.19 ppm; δX = 205 Hz / 100 MHz = 2.05 ppm;

M

37

H C

H

JAD= < 1 Hz; JAM = 8.2 Hz; JAX = < 1 Hz; JDM = 15.8 Hz; JDX = 6.9 Hz; JMX = 1.6Hz;

D

C

A

C CH3 X

Please Keep Absolutely Confidential

Problem 329

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman

5 Spin System AMX3

Chemical Shifts

Problem 330

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

3 Spin System A2X

δA = 80 Hz / 60 MHz = 1.33 ppm δM = 220 Hz / 60 MHz = 3.67 ppm δX = 320 Hz / 60 MHz = 5.33 ppm

Of the 6 isomeric anilines, only compounds 4 and 6 have the correct symmetry to give a spectrum with only two chemical shifts in the aromatic region, in the ratio 2:1. Both 4 and 6 would give A2X spin systems. The measured coupling constant is 7.7 Hz which is in the range for protons which are ortho to each other. Compound 4 is the correct answer.

December 2007

38

NH2 Br

Br

HA

HA HX

Please Keep Absolutely Confidential

Copyright: Copying or duplicating these solutions in any form is strictly prohibited

ORGANIC STRUCTURES FROM SPECTRA – 4th EDITION L D Field, S Sternhell and J R Kalman

Problem 331

Problem 332 All of the protons in the 1H spectrum 1,5-dichoronaphthalene have protons which are ortho to them. This means that every proton must have at least one large (>7 Hz) ortho coupling. The spectrum has one proton (at δ 7.1) which has only a small coupling so this cannot be the spectrum of 1,5-dichloronaphthalene.

The spectrum is obtained after D2O exchange so the carboxylic acid and phenolic protons will not be present and the spectrum only contains the aromatic and vinylic protons. The spectrum shows 6 distinct resonances therefore compounds 5 and 6 can be eliminated because they would each have only 4 resonances (on symmetry grounds).

The spectrum is an AMX spectrum with couplings between A and X of about 8.3 Hz (typical of an ortho coupling) and coupling between M and X of about 2.7 Hz (typical of a meta coupling). Two possible structure are given below.

The proton at about δ 7.1 shows no large coupling (> 7 Hz), this means that it has no protons ortho to it. This eliminates compounds 1 and 2 since all protons in these compounds will have at least one large ortho coupling. Compounds 3 and 4 differ by the stereochemistry at the double bond. The proton at δ 6.4 is clearly one of the vinylic protons and it is coupled to the other vinylic proton at δ 7.6. The coupling constant is 16 Hz and this characteristic of vinylic protons which are trans to each other. The correct answer is compound 3. OH

COOH

HM

HM

Cl HX HA

HA

Cl

HX

HX

Cl

HA

2,7-dichloronaphthalene December 2007

39

HM Cl HX

HM

HA

2,6-dichloronaphthalene