Studies on sugar nitro-olefins. Part 6. Synthesis of (3R)-3,5,6,7-tetrahydro-2-hydroxyimino-3-(penta-O-acetylpentitol-1-yl)benzofuran-4(2H)-ones from 3,4,5,6,7-penta-O-acetyl-1,2-dideoxy-1-nitrohept-1-enitols and cyclohexane-1,3-diones

Abstract

3,4,5,6,7-Penta-O-acetyl-1,2-dideoxy-1-nitro-D-galacto- and -D-gluco-hept-1 -enitol react with cyclo-hexane-1,3-diones yielding (3R)-3,5,6,7-tetrahydro-2-hydroxyimino-3-(1,2,3,4,5-penta-O-acetyl-D-galacto- or -D-gluco-pentitol-1 -yl)bentofuran-4(2H)-ones (5) that arise from cyclization of the intermediate Michael adducts. Acetylation of compounds (5) gives the oxime acetates (6). The structures of compounds (5) and (6) were established on the basis of their spectral properties (u.v., i.r., mass, and ¹H and ¹³C n.m.r.).