Stereocontrolled Glycoside and Glycosyl Ester Synthesis. Neighboring Group Participation and Hydrogenolysis of 3-(2‘-Benzyloxyphenyl)-3,3-dimethylpropanoates

[reaction: see text] The 2-O-[3-(2'-benzyloxyphenyl)-3,3-dimethylpropanoate] and 2-O-[3-(2'-benzyloxy-4',6'-dimethylphenyl)-3,3-dimethylpropanoate] esters enable the synthesis of a range of beta-glucosides and alpha-mannosides through neighboring participation in excellent yield, and are removed by hydrogenolysis in concert with the cleavage of benzyl esters in the presence of other esters making them particularly well suited to the stereocontrolled synthesis of glycosyl esters.