3-[(S)-(2-tert-butyldimethylsilyloxy)-2-phenylacetyl]-3-[5-methoxy-1,2-dihydrobenzocyclobuten-1-yl]-6,9-divinyl-1-oxaspiro[4,4]nonan-2-one                                                                                                                                                              在
                                                                                                                                                                                 
吡啶   、                                                                                                  
氢氟酸                                                                                                                                  作用下,
                                                                                                                                                                                                                            生成                                                 
(8β,9α,14α)-11β-[2(S)-2-hydroxy-2-phenylacetyl]-11α,13α-(γ-lactone)-2-methoxy-17α-vinylgona-1,3,5(10)-triene   、                                                                                             
(8α,9β,14β)-11β-[2(S)-2-hydroxy-2-phenylacetyl]-11α,13α-(γ-lactone)-2-methoxy-17β-vinylgona-1,3,5(10)-triene