Syntheses of 2-Amino-2,3-dideoxy-l- and -d-Ribohexose by Utilizing an O→N Acetyl Migration

2-Amino-2,3-dideoxy-l- and -d-ribohexose (1land 1d) were synthesized from 2-amino-2-deoxy-l- and -d-glucose, respectively, through a reaction sequence which involves 3-O→2-N acetyl migration of methyl 3,4,6-tri-O-acetyl-2-amino-2-deoxy-β-l- and -d-glucopyranoside (3land 3d). A preparative method of methyl 4,6-di-O-acetyl-2-amino-2-deoxy-β-d-glucopyranoside (11d) is given.