Peptide-catalyzed diastereo- and enantioselective cyclopropanation of aromatic α,ß-unsaturated aldehydes.

Highly diastereo- and enantioselective cyclopropanation of aromatic α,ß-unsaturated aldehydes was achieved using a resin-supported peptide catalyst under aqueous conditions. In the peptide sequence, the residue possessing an oxygen atom with the appropriate length of the side chain was essential for attaining good diastereoselectivity.