Synthesis of Kaitocephalin Facilitated by Three Stereoselective Allylic Transposition Reactions

A stereoselective synthesis of kaitocephalin is described. The central strategy is based on chirality transfer reactions of three secondary alcohols derived from L-arabinose. The Overman rearrangement of an alpha, beta-unsaturated ester, and intramolecular anti-type S(Nu)2' reaction constructed a beta-hydroxy-alpha, alpha-disubstituted amino acid moiety. The third chirality transfer reaction is the Ichikawa rearrangement. These stereoselective reactions successfully established the three contiguous stereocenters embedded in kaitocephalin.