A SYNTHESIS OF METHYL 2,3,6-TRIDEOXY-ALPHA-D-ERYTHRO-HEXOPYRANOSIDE (METHYL ALPHA-AMICETOSIDE)

The title glycoside 7, the parent sugar of which is a constituent of the antibiotic amicetin, was synthesized in a sequence of high-yielding steps from methyl 4,6-O-benzylidene-2,3-dideoxy-α-D-erythro-hex-2-enopyranoside (1), and was characterized as the crystalline 4-(3,5-dinitrobenzoate) (10). Hydrogenation of the 2,3 double bond in 1, followed by treatment of the resultant saturated glycoside (2) with A-bromosuccinimide, gave methyl 4-O-benzoyl-6-bromo-2,3,6-trideoxy-α-D-erythro-hexopyranoside (3). Treatment of 3 with potassium iodide in N,N-dimethylformamide gave the crystalline 6-iodo analog 5, which, after saponification to the 4-hydroxy derivative 6 and subsequent hydrogenation, gave the glycoside 7. The structures of all products and intermediates were supported by 100-MHz nmr spectral data. © 1969, American Chemical Society. All rights reserved.