Syntheses of optically active, unusual, and biologically important hydroxy-amino acids from D-glucosamine

Manipulation of D-glucosamine as a chiral pool including stereoinversion of the C3-hydroxyl group, degradation of the C6-carbon, and/or one carbon homologation at the C1-position realized chiral syntheses of (2S,3S)-dihydroxy-(4S)-amino acid moieties, important structural components of a gastroprotective substance AI-77-B and a group of antitumor substances calyculins.