Eleonora Shkolnik

A convenient method for enzymatic benzyl-alkyl transesterification under mild neutral conditions

Abstract Lipases from Candida cylindracea and from Pseudomonas fluorescens efficiently catalyse the benzyl to alkyl transesterification in organic solvents under mild conditions in nearly quantitative yields.

Resolution of racemic sterically hindered secondary alcohols via enzymatic alcoholysis of their esters. The first enzymatic preparation of optically pure 2,2,2-trifluoro-1-(9-anthryl)ethanols.

An approach has been developed which exploits the non aqueous enzymatic alcoholysis reaction for resolution of racemic sterically hindered secondary alcohols. The method was used effectively in the first enzymatic preparation of both enantiomers of the title compound via porcine pancreatic lipase catalysed alcoholysis of its butyrate ester. A considerable enhancement of the reaction rate was achieved by dispersion of the powdered enzyme preparation on aluminium oxide. A facile procedure was developed for separating the (R)-alcohol product from the unreactive (S)-butyrate ester and for the hydrolysis of the latter into the (S)-alcohol. The preparative usefulness of the resolution procedure is demonstrated by the convenience of the scaled-up enzymatic experiment carried out on 370 g of substrate in an ordinary flat bottom flask.