Acyclic stereoselection. 54. Extending the scope of the Evans asymmetric aldol reaction: preparation of anti and "non-Evans" syn aldols
                                
                                    
                                        作者:Michael A. Walker、Clayton H. Heathcock                                    
                                    
                                        DOI:10.1021/jo00020a006
                                    
                                    
                                        日期:1991.9
                                    
                                    The Evans reagent, imide 1, reacts with aldehydes under Lewis acid catalysis to give anti or ''non-Evans'' syn aldols 5 or 6, depending on the reaction conditions.  This discovery considerably amplifies the synthetic utility of these important reagents for asymmetric synthesis.