Stereoselective synthesis of C-glycosylphosphonates from their ketols. Reconsideration of an abandoned route
                                
                                    
                                        作者:Alessandro Dondoni、Alberto Marra、Claudia Pasti                                    
                                    
                                        DOI:10.1016/s0957-4166(99)00477-2
                                    
                                    
                                        日期:2000.1
                                    
                                    Isosteric phosphonate analogues of glycosyl 1-phosphates have been obtained by addition of LiCH2P(O)(OMe)(2) to glyconolactones followed by Et3SiH-TMSOTf reductive dehydroxylation of the resultant ketols. The compounds prepared include four beta-linked pyranose derivatives (D-galacto, 2-azido-2-deoxy-D-galacto, D-gluco, D-manno) and one beta-linked furanose derivative (D-manno). In the latter case the ketol was activated as its 2-acetate. In agreement with an observation in another laboratory, the dehydroxylation of a model ketol phosphonate failed with the use of Et3SiH-BF3. Et2O. (C) 2000 Elsevier Science Ltd. All rights reserved.