Lipase-catalyzed Irreversible Transesterification of Secondary Alcohols Using Isopropenyl Acetate

Asymmetric acetylation of a set of secondary alcohols with the innocuous acyl donor isopropenyl acetate catalyzed by a lipase from Pseudomonas cepacia immobilized on ceramic particles (PSL-C) in toluene as organic medium afforded the chiral alcohols and the corresponding acetates in high enantiomeric excess (up to 99%). An effective baseline separation of the enantiomers of both substrate and product was performed in one analysis without derivatization using gas chromatography on a new chiral stationary phase (CSP) Chirasil-β-Dex containing an undecamethylene spacer (C11-Chirasil-Dex).