Phenacyl-triphenyl-arsonium   、                                                                                      
methyl 2,2,6-trimethyl-2H-pyran-5-carboxylate                                                                                                                                                              在
                                                                                                                                                                                 
potassium tert-butylate                                                                                                                                  作用下,
                                                                                                                                                                                                                            生成                                                 (1R,2R,3R)-1-Acetyl-2-benzoyl-3-(2-methyl-propenyl)-cyclopropanecarboxylic acid methyl ester   、                                                                                             (1R,2S,3S)-1-Acetyl-2-benzoyl-3-(2-methyl-propenyl)-cyclopropanecarboxylic acid methyl ester