Stereoselective Synthesis of (−)-Cytoxazone and (+)-5-Epi-cytoxazone

Abstract

Abstract A novel, stereo selective synthesis of (−)-cytoxazone 1a and stereoselective synthesis of (+)-5-epi-cytoxazone 1b were achieved via stereoselective Grignard addition of vinylmagnesium bromide on N-Boc al ehyde obtained from p-hydroxy-d-phenylglycine 2 followed by cyclization of N-Boc alcohol 6, ozonolysis and reduction to get (+)-5-epi-cytoxazone. Compound 6 underwent mitsunobu conditions, deprotection of ester followed by cyclization of N-Boc alcohol to get (−)-cytoxazone.