2,3,5,6-tetramethylidene-7-oxabicyclo[2.2.1]heptane   、                                                                                      
rel-(1R,4S,6R,6aR,8s,9aS,10S,12R,15S,17R,17aR,19r,20aS,21S)-1,4:6,21:8,19:10,17:12,15-pentaepoxy-1,4,6,6a7,8,9,9a,10,12,15,17,17a,18,19,20,20a,21-octadecahydrononacene                                                                                                                                                                                              以
                                                                                         
甲苯                                                                                  为溶剂,
                                                                                                                                                    反应 7.0h,
                                                                                                                以69%的产率得到rel-(1R,4S,4aS,6r,7aR,8R,10S,10aS,12r,13aR,14R,17S,17aS,19r,20aR,21R,23S,23aS,25r,26aR)-1,4:6,25:8,23:10,21:12,19:14,17-hexaepoxy-1,4,4a,5,6,7,7a,8,10,10a,11,12,13,13a,14,17,17a,18,19,20,20a,21,23,23a,24,25,26,26a-octacosahydro-2,16:3,15-dimethenound...