Successful glycosynthase-mediated reactions have been performed on 6-O-benzyl-, 6-O-(4-nitrobenzyl)-, and 6-O-benzoyl-d-glucopyranose to give 1,2-β- and 1,3-β-d-glycosylated products; 4-O-benzyl-d-xylopyranose gave only a 1,2-β-glycosylated product. A rationale is presented for these rather unusual results.