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 α,β-unsaturated ester, and intramolecular anti-type SN2′ reaction constructed a β-hydroxy-α,α-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.