1-甲基吲哚 、
tetrahydro-4-(prop-2-ynyl)-2H-pyran-4-carbaldehyde 在
silver trifluoromethanesulfonate 作用下,
以
氯仿 为溶剂,
生成 4,9-dimethyl-1,4-bis(1-methyl-1H-indol-3-yl)-1,2',3,3',4,5',6',9-octahydrospiro[carbazole-2,4'-pyran] 、 4,9-dimethyl-1,4-bis(1-methyl-1H-indol-3-yl)-1,2',3,3',4,5',6',9-octahydrospiro[carbazole-2,4'-pyran]