Septanose Carbohydrates. III. Oxidation-Reduction Products From 1,2-3,4-Di-O-isopropylidene-α-D-glucoseptanose: Preparation of L-Idose Derivatives

Abstract

Oxidation of 1,2:3,4-di-O-isopropylidene-α-D-glucoseptanose (1a) with dimethyl sulfoxide and acetic anhydride has yielded methylthiomethyl ether (1b), ketone (2), and a novel product (3). Reduction of (2) gave (1a) and its L-ido isomer (4a) which yielded the mono-O-isopropylidene compound (5a) on aqueous acid hydrolysis. Treatment of (5a) with acidified acetone gave (4a) and 1,2:4,5-di-O-isopropylidene-β-L- idoseptanose (7a). Reaction of (2) with methylmagnesium iodide yielded the two 5-C-methyl compounds (8) and (9). Hydrolysis of (8) and (9) gave 5-C-methyl-D-glucose (10) and 5-C-methyl-L-idose (11), respectively, as crystalline compounds which yielded crystalline pentaacetates on acetylation. Treatment of the p-toluenesulfonate (1c) with lithium benzoate in dimethylformamide gave the benzoate of (4a) and an elimination product (17). Reaction of (1c) with sodium methoxide in methanol yielded (17) and the isomeric elimination product (18).