5-[1-(4,4-dimethyl-5-thioxopyrrolidin-2-ylidene)-ethyl]-3,4-dimethyl-1H-pyrrole-2-carboxylic acid tert-butyl ester   、                                                                                      alkaline earth salt of/the/ methylsulfuric acid                                                                                                                                                              在
                                                                                                                                                                                 
三氟乙酸                                                                                                                                  作用下,
                                                                                                                                                                                                                            以34%的产率得到5-[1-(4,4-dimethyl-5-methylsulfanyl-3,4-dihydropyrrol-2-ylidene)-ethyl]-3,4-dimethyl-1H-pyrrole-2-carbaldehyde