One-step, stereocontrolled synthesis of glycosyl 1-phosphates, uridine-5 '-diphosphogalactose, and uridine-5 '-diphosphoglucose from unprotected glycosyl donors
S. Hanessian et al., One-step, stereocontrolled synthesis of glycosyl 1-phosphates, uridine-5 '-diphosphogalactose, and uridine-5 '-diphosphoglucose from unprotected glycosyl donors, J AM CHEM S, 120(51), 1998, pp. 13296-13300
The reaction of 2-(1,2-trans-glycopyranosyloxy)-3-methoxypyridines (MOP gly
cosides) with phosphoric acid leads to the corresponding 1,2-cis-1-phosphat
es in good yield and excellent stereoselectivity. 1-Phosphate esters of alp
ha-D-glucopyranose, alpha-D-galactopyranose, and 2-azido-2-deoxy-alpha-D-ga
lactopyranose were thus prepared without recourse to protective groups. In
the L-fucose series, the major product was the alpha-L-fucosyl I-phosphate.
An alternative method that relies on neighboring group participation allow
ed the preparation of a protected beta-L-fucosyl I-phosphate. Reaction of u
nprotected beta-D-glucopyranosyloxy and beta-D-galactopyranosyloxy MOP dono
rs with uridine diphosphoric acid gave UDP-Glc and UDP-Gal with preponderan
ce of the desired alpha-anomeric configuration.