Exp3 Adn Orga

EXPERIMENT 3: OXIDATION OXIDATION OF CYCLOHEXANOL WITH PCC ON A SILICA GEL SUBSTRATE

OBJECTIVE •

To investigate the oxidation of cyclohexanol to cyclohexanone with PCC on a

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silica gel substrate To investigate test of TLC To determine the IR spectrum of cyclohexanone

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INTRODUCTION

Oxidation reactions of alcohols greatly increase the synthetic usefulness of these compounds. Only primary and secondary alcohols can be easily easily oxidied with the former converted to aldehydes or carboxylic acids and the latter to the corresponding !etones. The strength and selectivity of oxidiing agents varies widely" the use of oxochromium#I$% amine reagents is fundamental for a number of organic oxidative transformations. Pyridinium chlorochromate #PCC% is the most commonly used of these reagents" due to its availability" stability stability and versatility. Oxidation with PCC generally  proceeds through a simple" one step reaction &

EQUIPMENTS AND INSTRUMENTS

'. Pestle and mortar  (. )agnetic stirrer  *. Rotatory evaporator  +. IR 

MATERIALS

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Cyclohexanol #,- '.'/% # .01 g2ml% .' g #'. mmol% Pyridinium chlorochromate #,- ('1.1/% .+* g #(. mmol% 3ilica gel #(* 4 + mesh% .+* g #for synthesis% 5ichloromethane Celite 3aturated 6aCl 7nhydrous 6a(3O+ 8thyl acetate Petroleum ether 3ilica gel #*9 : mesh% for filtering 3ilica gel #(*9 + mesh% for column chromatograpy

PROCEDURE

'. PCC and silica gel #(*o;+oo mesh was combined and grind with a pestle and mortar and a light orange powder was formed. (. The powder was added to (1ml round bottom flas! along with /ml dichloromethane. *. Then the cyclohexanol was added and stirred for (o;*o minutes. +. The solution was tested with TLC for every five minutes. 1. 7fter the reaction was completed" the reaction solution was diluted with 'oml of ether and the solution was filtered through a pipet containing a cotton plug" 'cm Celite" *cm silica gel #*1;:o mesh. /. The solution was extracted with (x1ml of water and saturated 6aCl solution. :. The solution was dried over anhydrous 6a(3O+ and the solvent was evaporated under vacuum. . ,ryhle #(''%. Organic chemistry #' th ed.%. Eohn -iley F 3ons" I6C. /0' pp.