1α,3β-bis(tert-butyldimethylsilyloxy)-20(R)-hydroxypregna-5,7,16-triene   、                                                                                      
sodium;hydride   、                                                                                      
15-冠醚-5   、                                                                                      (Z)-1-bromo-4-methyl-4-triethylsilyloxy-2-pentene                                                                                                                                                              在
                                                                                                                                                                                 
正己烷   、                                                                                                  
乙酸乙酯                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
四氢呋喃                                                                                  为溶剂,
                                                                                                                                                                                        以ethyl acetate=30:1, developed once) to give the title compound as a colorless oil (70.3 mg, 85%)的产率得到1α,3β-bis(tert-butyldimethylsilyloxy)-20(R)-{(Z)-(4-methyl-4-triethyl-silyloxy-2-pentenyloxy)}pregna-5,7,16-triene