作者:Stephen R. Wilson、A.M. Venkatesan、C.E. Augelli-Szafran、A. Yasmin                                    
                                    
                                        DOI:10.1016/s0040-4039(00)79918-7
                                    
                                    
                                        日期:1991.5
                                    
                                    A synthesis of 1,25-dihydroxy-vitamin D3 using a new acetylenic Ring-A precursor is described.  Ring-A synthons 4a or 4b can be prepared in homochiral form by a disastereoselective diazoester cyclization.