[(3aR,7aR)-7a-(tert-Butyl-dimethyl-silanyloxy)-3a,5,5-trimethyl-4-methylene-hexahydro-benzofuran-(2E)-ylidene]-acetic acid ethyl ester                                                                                                                                                              在
                                                                                                                                                                                 
四丁基氟化铵                                                                                                                                  作用下,
                                                                                                                                                                                                                            生成                                                 (R)-3a,5,5-Trimethyl-4-methylene-2-oxo-3,3a,4,5,6,7-hexahydro-2H-indene-1-carboxylic acid ethyl ester