1-(diphenylmethyl)-3-(3-hydroxy-5,6,7,8-tetrahydronaphthalen-2-yl)-1,3-dihydro-2H-indol-2-one 、
1-(diphenylmethyl)-3-(2-hydroxy-4-methoxy-5-methylphenyl)-1,3-dihydro-2H-indol-2-one 以1-(diphenylmethyl)-5′,6′,7′,8′-tetrahydrospiro[indole-3,3′-naphtho[2,3-b]furan]-2(1′H)-one was obtained (81%) as a colorless solid的产率得到1-(diphenylmethyl)-5',6',7',8'-tetrahydrospiro[indole-3,3'-naphtho[2,3-b]furan]-2(1H)-one