SYNTHESIS AND CRYSTAL STRUCTURE OF METHYL 4,6-DIDEOXY-4-(3-DEOXY-L-GLYCERO-TETRONAMIDO)-2-O-METHYL-ALPHA-D-MANNOPYRA NOSIDE, THE METHYL ALPHA-GLYCOSIDE OF THE TERMINAL UNIT, AND PRESUMED ANTIGENIC DETERMINANT, OF THE O-SPECIFIC POLYSACCHARIDE OF VIBR

摘要

Methyl 4-azido-4,6-dideoxy-3-O-benzyl-alpha-D-mannopyranoside and its analogous 3-O-(4-methoxybenzyl) derivative were methylated and the 2-O-methyl derivatives formed were converted into methyl 4-amino-4,6-dideoxy-2-O-methyl-alpha-D-mannopyranoside. Reaction of the latter with 3-deoxy-L-glycero-tetronolactone gave the methyl glycoside of 4,6-dideoxy-4-(3-deoxy-L-glycero-tetronamido)-2-O-methyl-alpha-D-mannopyra nose, the monosaccharide that is reported to be the terminal moiety of the O-specific polysaccharide of Vibrio cholerae 0:1, serotype Ogawa. The unit cell packing of the compound, which crystallized as a monohydrate, differs from that of the previously described crystalline compound lacking the 2-O-methyl group. The unmethylated sugar is the terminal moiety of the O-specific polysaccharide of Vibrio cholerae 0:1, serotype Inaba. The crystal structure of methyl 4,6-dideoxy-2-0-methyl-4-trifluoroacetamido-alpha-D-mannopyranoside is also described. [References: 18]