One-pot deracemisation of an enol acetate derived from a prochiral cyclohexanone

A one-pot method for the deracemisation of the enol acetate 1 derived from the prochiral 4,4-disubstituted cyclohexanone 2 has been developed using the combination of Pseudomonas fluorescens lipase and potassium t-butoxide/isopropenyl acetate to give the enantiomerically pure enol acetate (S)-1 in 82% yield. Calculations based on the inherent enantioselectivity of the lipase (E) allowed an estimation of the optimum theoretical conversion for each enzyme step prior to recycling the ketone.