Branched-chain sugars. Part II. Characterization of methyl 2,4-di-O-acetyl-3,6-dideoxy-3-C-methyl-3-nitro-α-L-glucopyranoside and some of its chemical transformations

Abstract

One of the nitro-acetates obtained by cyclization with nitroethane of the dialdehyde (1)(prepared by oxidation of methyl α-L-rhamnopyranoside with sodium periodate) followed by acetylation has been unambiguously characterized as methyl 2,4-di-O-acetyl-3,6-dideoxy-3-C-methyl-3-nitro-α-L-glucopyranoside (2). The configuration at the tertiary centre of the latter compound was established with reasonable certainty by the ready solvolysis of both sulphonyloxy-groups from the derived methyl 3-acetamido-3,6-dideoxy-3-C-methyl-2,4-di-O-methyl-sulphonyl-α-L-glucopyranoside (7) under conditions requiring participation by the neighbouring 3-acetamidogroup. Chemical transformations of the nitro-acetate (2) and methyl 3-acetamido-3,6-dideoxy-3-C-methyl-α-L-glucopyranoside (6), aimed at making a 2-deoxy-derivative, are described.