Epoxidation of glycals with oxone–acetone–tetrabutylammonium hydrogen sulfate: a convenient access to simple β-d-glycosides and to α-d-mannosamine and d-talosamine donors
作者:Dominique Lafont、Joseph D’Attoma、Rejane Gomez、Peter G. Goekjian
DOI:10.1016/j.tetasy.2011.06.027
日期:2011.6
The addition of a phase transfer catalyst during the epoxidation of perbenzylated glycals with oxone-acetone under biphasic conditions allows their complete epoxidation. The epoxides were readily transformed into methyl 1,2-trans-beta-D-glycosides or 1,2-trans-beta-D-glycopyranosyl azides (D-gluco and-D-galacto configurations) bearing a free hydroxyl group at the 2-position. These glycosyl azides were converted to alkyl 1,2-trans-2-acetamido-2-deoxy-alpha-D-pyranosides or alkyl 2-allyloxycarbonylamino-2deoxy-alpha-D-pyranosides (D-manno and D-talo configurations) by a Staudinger reaction and a double inversion of configuration at C-1 and C-2. (C) 2011 Elsevier Ltd. All rights reserved.