(3aR,4R,6aS,7R,9R,9aR,9bR)-9-(2-Carboxy-propyl)-4,7-dimethyl-1-methylene-decahydro-phenalene-3a-carboxylic acid   、                                                                                      
碘甲烷                                                                                                                                                              在
                                                                                                                                                                                 
lithium diisopropyl amide                                                                                                                                  作用下,
                                                                                                                                                                                                                            生成                                                 
(3aR,4R,6aS,7R,9R,9aR,9bR)-9-(2-Carboxy-2-methyl-propyl)-4,7-dimethyl-1-methylene-decahydro-phenalene-3a-carboxylic acid