Authors: Gopalpur Nagendrappa
Publish Date: 2008/08/27
Volume: 13, Issue: 4, Pages: 355-368
Abstract
Benzoin condensation is an important carboncarbon bond forming reaction It is achieved by generating an acyl anion equivalent from one aldehyde molecule which adds to a second aldehyde molecule The reaction is traditionally catalysed by a cyanide ion Cyanohydrin anion is the first intermediate and is the precursor to the acyl anion equivalent Cyanohydrins are found in plants as glycosides A reaction completely analogous to benzoin condensation occurs in our body which however neither involves cyanohydrin intermediate nor is catalysed by cyanide ion It is catalysed by the thiazolium moiety of the coenzyme thiamine pyrophosphate TPP This article shows the common links and inclusive chemistry aspects among cyanohydrin formation naturally occurring cyanohydrins conversion of cyanohydrins to benzoins/acyloins the role of vitamin B1 thiamine and the use of thiazolium compounds in benzoin/acyloin condensationG Nagendrappa retired from Bangalore University Bangalore is presently Professor and Head of the Department of Medicinal Chemistry Sri Ramachandra University Porur Chennai His main work is in the areas of organosilicon chemistry organic synthesis reaction mechanism and synthetic methodologies
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