Addition of pseudohalogens to unsaturated carbohydrates. III. Synthesis of 3-deoxy-3-C-nitromethyl-D-allose, a branched-chain nitro sugar

Abstract

Addition of nitryl iodide to 3-deoxy-1,2:5,6-di-O-isopropylidene-3-methylene-α-D-ribo-hexofuranose (2), followed by treatment of the product with sodium borohydride, gave crystalline 3-deoxy-1,2:5,6-di-O-isopropylidene-3-C-nitromethyl-α-D-allofuranose (3); the branched-chain unsaturated sugar (2) was prepared by way of a Wittig reaction with 1,2:5,6-di-O-isopropylidene-α-D-ribo-hexofuranos-3-ulose (1). Acid-catalyzed hydrolysis of 3 afforded 3-deoxy-3-C-nitromethyl-D-allose, which exists predominantly in the β-D-furanose form (4).