Formation and structure elucidation of two novel spiro[2H-indol]-3(1H)-ones

Abstract

The molecular structures of two byproducts 1,1 ''-diphenyl-3',4'-dihydrodispiro[indole-2,2'-furan-5',2 ''-indole]-3,3 ''(1H, 1 '' H)-dione (3) and 1,5'-diphenyl-4,5-dihydro-3'H-spiro [indole-2,2'-pyrano [3,2-b] indol]-3(1H) -one (4), which accompanied the rearrangement of 3-hydroxy-3-methyl-1-phenylquinoline-2,4(1H,3H)-dione (1)to 2-hydroxy-2-methyl-1-phenyl-1,2-dihydro-3H-indol-3-one (2), have been elucidated by NMR, MS, and X-ray diffraction. Copyright (c) 2007 John Wiley & Sons, Ltd.