Preparation of new omega-aldehydoalkyl 1-thio-D-glycopyranosides, and their coupling to bovine serum albumin by reductive alkylation.

Synthesis of two omega-aldehydoalkyl 1-thioglycosides of D-glucopyranose and of D-galactopyranose is described. 3-Oxopropyl and 2-oxoethyl 1-thioglycosides were prepared by treating a tetra-O-acetyl-1-thioaldose with either acrolein or 2-bromo-acetaldehyde, followed by O-deacetylation under mild conditions. These omega-aldehydoalkyl 1-thioglycosides were successfully attached to bovine serum albumin (BSA) by reductive alkylation as described previously. With the 3-oxopropyl 1-thioglycosides, much higher levels of sugar attachment (e.g., approximately 80 mol of sugar per mol of BSA) were attained than hitherto possible with any sugar derivative tested.