Branched-chain sugars. Part 11. An approach to the synthesis of D-evernitrose via the addition of iodine azide to a C-methylene sugar

Abstract

Methyl 3-acetamido-2,3,6-trideoxy-3-C,4-O-dimethyl-α-D-arabino-hexopyranoside (16), a known precursor of D-evernitrose, has been synthesised via the addition of iodine azide to methyl 4,6-O-benzylidene-2,3-dideoxy-3-Cmethylene-α-D-erythro-hexopyranoside (6). One of the adducts isolated from this reaction was assigned the structure methyl 3-azido-4,6-O-benzylidene-2,3-dideoxy-3-C-(iodomethyl)-α-D-arabino-hexopyranoside (9) by analogy and from the fact that ring-closure and N-acetylation gave the spiro-N-acetylaziridine (11), whose structure was secured by X-ray crystallography. The corresponding spiro-aziridine (10) was transformed into (16) in five steps.