8-(6-hydroxy-2,3-dihydrobenzofuran-5-yl)-6-(((R)-tetrahydrofuran-2-yl)methyl)-6,8-dihydro-2H-[1,4]dioxino[2,3-f]indol-7(3H)-one 、
1-(diphenylmethyl)-3-(2-hydroxy-4-methoxy-5-methylphenyl)-1,3-dihydro-2H-indol-2-one 以6-(((R)-tetrahydrofuran-2-yl)methyl)-2,3,5′,6′-tetrahydro-2′H-spiro[[1,4]dioxino[2,3-f]indole-8,3′-benzofuro[6,5-b]furan]-7(6H)-one was obtained (39%) as a colorless solid的产率得到6-(((R)-tetrahydrofuran-2-yl)methyl)-2,3,5',6'-tetrahydro-2'H-spiro[[1,4]dioxino[2,3-f]indole-8,3'-benzofuro[6,5-b]furan]-7(6H)-one