Helvetica Chimica Acta

Photochemical Synthesis of Cyclic 2??(2, 2??Dimethylpropylidene)??1, 3??dicarbonyl Compounds

K Hobel, P Margaretha

Index: Hobel, Klaus; Margaretha, Paul Helvetica Chimica Acta, 1989 , vol. 72, p. 975 - 979

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Citation Number: 10

Abstract

Abstract Photolysis (λ= 254 nm) of 4-(t-Bu)-substituted [b]-fused bi-and tricyclic pyrandiones 5 affords title compounds 4 in good yields as well as small amounts of spiroalkanediones 8. The alkyl-substitution pattern at C (4) of the pyran ring in 5 determines the relative amount of α vs. β-cleavage products obtained from the primarily formed acyl-vinyloxy biradical.