.alpha.-Amino acids as chiral educts for asymmetric products. Chirospecific syntheses of methyl L-sibirosaminide and its C-3 epimer from L-allothreonine
.alpha.-Amino acids as chiral educts for asymmetric products. Chirospecific syntheses of methyl L-sibirosaminide and its C-3 epimer from L-allothreonine