Epoxidation of C-branched glycals: unexpected stereochemical results and their theoretical rationale
作者:Christiane Ernst、Manuel Piacenza、Stefan Grimme、Werner Klaffke
DOI:10.1016/s0008-6215(02)00406-8
日期:2003.1
This paper describes the synthesis of C-3 methyl-branched glycosides by epoxidation of partially unblocked L-configured glycals. The stereochemical result depends on the orientation of the allylic hydroxyl group. A theoretical explanation is presented, based on the conformational preferences of the respective glycal half-chair conformations that were estimated by applying the BP density functional and a valence triple-zeta basis set. (C) 2002 Elsevier Science Ltd. All rights reserved.