Peptide-catalyzed regio- and enantioselective reduction of α,β,γ,δ-unsaturated aldehydes.

A resin-supported peptide catalyst (see box in the scheme) was used in the title reaction. The inherent regioselectivity was overcome by the peptide catalyst to promote the 1,6-selective reaction prior to 1,4-reduction. High stereoconvergence was also achieved when using a mixture of geometric isomers of the starting aldehydes. Ach=1-amino-1-cyclohexanecarboxylic acid.