Enantioselective reduction of prochiral aryl ketones using a novel chiral auxiliary derived from a labdane diterpene

Abstract

A novel chiral 2-methoxy-1,3,2-dioxaborolane derived from 2α,3α-dihydroxycativic acid, a labdane-type diterpene isolated from aerial parts of Baccharis scandens DC., is reported as a highly effective chiral auxiliary. This compound has been successfully used in the borane dimethyl sulfide complex-mediated asymmetric reduction of prochiral aryl ketones at room temperature. Very good chemical yields (up to 89%) and high enantioselectivities were obtained.