Tetrahedron

1-Acyl-2-cyclopentenes and 5-acylbicyclo [2.1. 0] pentanes: photochemical and thermal isomerizations

K Schaffner

Index: Schaffner,K. Tetrahedron, 1976 , vol. 32, p. 641 - 653

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Citation Number: 46

Abstract

The photochemistry of 1-acyl-2-cyclopentenes varies with the nature of the acyl group. On direct irradiation the aldehyde eliminates carbon monoxide in the singlet excited state, and the aroyl compounds cleave to allyl-aroyl radical pairs both from the singlet and triplet states. In competition to α-cleavage the methyl ketones isomerize in an allylic 1, 3-acetyl shift. The lowest-lying reactive triplet of these methyl ketones, characterized as a 3 (π, π*) state in ...