(E)-2-(1-benzoyl-2-oxoindolin-3-ylidene)acetate 、
methyl phenyl ketene 在
(S)-5-{bis[3,5-bis(trifluoromethyl)phenyl](hydroxy)methyl}-2-phenyl-6,7-dihydro-5H-pyrrolo[2,1-c]-1,2,4-triazol-2-ium tetrafluoroborate 、
caesium carbonate 作用下,
以
二氯甲烷 为溶剂,
生成 ethyl (3R,4R)-9-benzoyl-3-methyl-2-oxo-3-phenyl-2,3,4,9-tetrahydropyrano[2,3-b]indole-4-carboxylate 、
ethyl 9-benzoyl-3-methyl-2-oxo-3-phenyl-2,3,4,9-tetrahydropyrano[2,3-b]indole-4-carboxylate 、 ethyl 9-benzoyl-3-methyl-2-oxo-3-phenyl-2,3,4,9-tetrahydropyrano[2,3-b]indole-4-carboxylate