Stereospecific α-methallylation of hydroxyaldehydes by silatropic ene cyclisation
                                
                                    
                                        作者:Jeremy Robertson、Michael J. Hall、Stuart P. Green                                    
                                    
                                        DOI:10.1016/j.tet.2009.01.117
                                    
                                    
                                        日期:2009.7
                                    
                                    We describe the thermal rearrangement of aldehydes bearing an alpha-(allyl- or crotylsilyl)oxy substituent. The transformations are best described mechanistically as intramolecular silatropic ene reactions based on stereoselectivity, kinetic and computed transition state data. The overall process constitutes a stereospecific (meth)allylation of alpha-hydroxyaldehydes, under neutral conditions, in which the hydroxyl protecting group is also the (meth)allylating agent. (C) 2009 Elsevier Ltd. All rights reserved.