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 ...