benzyl 2-formyl-3-methylpyrrole-4-carboxylate 、 tert-butyl 4,6-bis(2-acetoxyethyl)-1-<2-(methoxycarbonyl)ethyl>-1',2,3,5-tetramethyltripyrrene-a-6'-carboxylate hydrobromide 在
三氟乙酸 作用下,
生成 4,6-bis(2-acetoxyethyl)-8-<(benzyloxy)carbonyl>-1-<2-(methoxycarbonyl)ethyl>-1',2,3,5,7,-pentamethyl-a,c-biladiene