Rearranjo di-pi-metano de derivados de 3-Fenil-Propeno com retiradores de elétrons em C1

Abstract

The photochemistry of derivatives of 1,1-dicyano-3-phenyl-propene was investigated. All compounds were dissubstituted at C1 by cyano or ester groups, or one of each; C3 had either one or two alkyl groups, besides the phenyl. The maln results were: (a) the quantum yields for di-pi-methane rearrangement depend on the nature the terminal electron-withdrawing substituents; (b) 1,1-dicyano-3-phenyl-butene shows the presence of two dlfferent mechanisms for cyclopropane formation, simultaneously; (c) compounds with at least. one terminal ester groups having a benzylic hydrogen, show photo-deconjugation as the preferred reaction pathway.