Diastereoselective addition reactions of furyl aldehydes using chiral boronates as auxiliary: Application to the enantioselective synthesis of 2,3-disubstituted furyl alcohols

matrix presented The addition reactions of various nucleophiles to a furyl aldehyde bearing a chiral boronate at the C-3 position furnished chromatographically separable diastereomers. The R diastereoselection was more favorable when no additive was added. Surprisingly, when lithium alkoxides were selected as additives, the S diastereoselection is superior instead. Further transformation of C-B bonds to C-C bonds was achieved by using standard Suzuki coupling conditions to give optically active 2,3-disubstituted furyl alcohols.