Five-membered 2,3-dioxo heterocycles. 2. Synthesis and [1,5]-sigmatropic rearrangement of 4-acyl-3-diphenylmethoxy-1,5-diphenyl-2,5-dihydropyrrol-2-ones

4-Acyl-1,5-diphenyltetrahydropyrrole-2,3-diones react with diphenyldiazomethane to give O-alkylation products, which upon heating undergo [1,5]-sigmatropic suprasurface rearrangement to form 4-[methyl- and 4-[-aryl(diphenylmethoxy)-methylene]-1,5-diphenyltetrahydropyrrole-2,3-diones.See [1] for Communication 1.Translated from Khimiya Geterotsiklicheskikh Soedinenii. No. 5, pp. 625–628, May, 1987.