KCS

Ferrier transformation of 3,4,6-tri-O-acetyl-D-glucal with methanol produced D-pseudoglucal. Deacetylation and t-butyldipnenylsilylation of 6-hydroxy group afforded methyl 6-O-(t-butyldiphenylsilyl)-2,3-dideoxy-α-D-erythro-hex-2-enopyranoside. Mitsunob reaction of this 4-hydroxy compound and debenzoylation also afforded methyl 6-O-(t-butyldiphenylsilyl)-2,3-dideoxy-α-D-threo-hex-2-enopyranoside. Carbamoylation of these two epimeric products yielded methyl 4-O-carbamoyl-6-O-(t-butyldiphenylsilyl)-2,3-dideoxy-α-D-erythro-hex-2-enopyranoside and methyl 4-O-carbamoyl-6-O-(t-butyldiphenylsilyl)-2,3-dideoxy-α-D-threo-hex-2-enopyranoside, respectively. Intramolecular addition reaction of these compounds in the presence of 10 mol% platinum (IV) chloride and excess amounts of chlorotrimethylsilane at room temperature produced 5-membered cyclic carbamates of 3-amino-2,3-dideoxy sugars. The stereochemistry of these cyclic carbamates was confirmed by NMR spectroscopy.