Synthesis of crystalline derivatives of 3-deoxy-d-gluco-heptofuranose

L. JERONCIC; A. FERNÁNDEZ CIRELLI; R. MUCHNIK DE LEDERKREMER

CARBOHYDRATE RESEARCH

Elsevier

Lugar: Amsterdam; Año: 1987 vol. 167 p. 175 - 186

0008-6215

Benzoylation ofD-glycero-D-gulo-heptono-1,4-lactone afforded 2,3,5,6,7-penta-O-benzoyl-D-glycero-D-gulo-heptono-1,4-lactone, which, by 3-deoxygenation, gave 2,5,6,7-tetra-O-benzoyl-3-deoxy-D-gluco-heptono-1,4-lactone (4) in 80% overall yield. In a similar way, 2,5,6,7-tetra-O-acetyl-3-deoxy-D-gluco-heptono-1,4-lactone was prepared. Disiamylborane reduction of compound 4 gave crystalline 2,5,6,7-tetra-O-benzoyl-3-deoxy-¦Â-D-gluco-heptofuranose (6), which was acetylated to give crystalline 1-O-acetyl-2,5,6,7-tetra-O-benzoyl-3-deoxy-¦Â-D-gluco-heptofuranose (7). Upon treatment of 6 with diazomethane-boron trifluoride etherate, methyl 2,5,6,7-tetra-O-benzoyl-3-deoxy-¦Â-D-gluco-heptofuranoside (8) was obtained. From the reaction mixture, the benzoylated ¦Â,¦Â¡ä-furanosyl disaccharide 11 was isolated. A higher yield (90%) of 8 was obtained by treatment of 7 with methanol and tin(IV) chloride. On O-debenzoylation of 8, methyl 3-deoxy-¦Â-D-gluco-heptofuranoside was obtained. Compound 11 was the sole product (82% yield) when 6 was treated with boron trifluoride-etherate in dichloromethane. O-Debenzoylation of 11 afforded crystalline 3-deoxy-¦Â-D-gluco-heptofuranosyl 3-deoxy-¦Â-D-gluco-heptofuranoside. O-Debenzoylation of 6 with sodium methoxide in chloroform afforded crystalline 3-deoxy-D-gluco-heptose, whose tautomeric equilibrium was studied by 13C-n.m.r. spectroscopy. Presented at the XIIIth International Carbohydrate Symposium, Ithaca, August 10¨C16, 1986.