Preparation of 1-- and 1--glucose esters by stereoselective acylation of metalated 2,3,4,6,-tetra-O-benzyl-D- glucopyranose

摘要

Anomerically pure 1-- and 1--esters of 2,3,4,6-Tetra- O- benzyl-D-glucopyranose have been prepared in high yield by controlling the stereochemistry of 1-O-acylation of appropriately protected D-glucose. 2,3,4,6-tetra-O-benzyl-D-glucopyranose is metalated with n-butyllithium in either tetrahydrofuran or anhydrous benzene and the metalated product acylated with an appropriate alkyl, alkenyl, or aryl acid chloride. Hydrogenation of the acyl glucopyranose, when derived from a saturated acid chloride, yields the appropriate 1-- or 1--D-glucose ester. Reaction in tetrahydrofuran produces the -anomer while reaction in anhydrous benzene produces the -anomer.