Di-tert-butylsilylene (DTBS) group-directed α-selective galactosylation unaffected by C-2 participating functionalities

We have discovered an unusual alpha-galactosylation using phenylthioglycoside of 4,6-O-di-tert-butylsilylene (DTBS)-protected galactose derivatives as a glycosyl donor, which was not hampered by the neighboring participation of C-2 acyl functionality such as NTroc and OBz. The power of the DTBS effect has been exemplified by the coupling reaction with various glycosyl acceptors. (C) 2003 Elsevier Ltd. All rights reserved.