Chemoenzymatic synthesis of α1- and α-acetoxylated cyclic ketones

alpha,beta-Unsaturated and saturated cyclic ketones were selectively oxidized at the alpha'- and alpha-positions using Mn(OAc)(3) and Pb(OAc)(4), respectively, resulting in high chemical yields. The resultant racemic alpha'- and alpha-acetoxylated substrates were resolved into corresponding enantiomerically enriched alpha'- and alpha-hydroxylated and acetoxylated compounds with 96-98% ee via PLE hydrolysis. The absolute configurations of alpha'-acetoxy-alpha,beta-unsaturated cyclic ketones were determined by transforming them into the corresponding saturated alpha-acetoxy cyclic ketones of known absolute configuration. (C) 2004 Elsevier Ltd. All rights reserved.