Pseudokobusine   、                                                                                      
氯甲酸-2,2,2-三氯乙酯                                                                                                                                                              在
                                                                                                                                                                                 
sodium hydroxide                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
二氯甲烷                                                                                  为溶剂,
                                                                                                                                                                                        以78%的产率得到2,2,2-trichloroethyl (1R,4aR,5R,5aS,7R,9R,9aR,11aR,12S,13S)-9,13-dihydroxy-1-methyl-8-methylene-11-oxododecahydro-2H-4a,9a,7-(epiethane[1,1,2]triyl)-5,1-(epiminomethano)dibenzo[a,d][7]annulene-14-carboxylate