(diphenylmethyl)-3-(5-hydroxy-2,3-dihydro-1,4-benzodioxin-6-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)-2,3-dihydrospiro[furo[2,3-f][1,4]benzodioxine-7,3′-indol]-2′(1′H)-one was obtained (85%) as a colorless solid的产率得到1'-(diphenylmethyl)-2,3-dihydrospiro[furo[2,3-f][1,4]benzodioxine-7,3'-indol]-2'(fH)-one