Helvetica Chimica Acta

Photochemische Reaktionen. 97 Mitteilung [1]. Zur Photochemie konjugierter Epoxy??diene II. Versuche mit (E)?螃漫?Jonyliden??epoxiden

AP Alder, HR Wolf, O Jeger

Index: Alder,A.P. et al. Helvetica Chimica Acta, 1978 , vol. 61, p. 2681 - 2696

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Citation Number: 11

Abstract

Summary Direct and sensitized excitation of the (E)-p-ionylidene-epoxides 1 and 4 leads to different types of isomerizations. Thus photocycloelimination to the cyclopropene-ketones 2 and 6 is only achieved by'(n, n*)-excitation (A= 254 nm), whereas 3 (n, n*)-excitation (3,> 280 nm, acetone) gives selective C (1'), 0-cleavage of the oxirane (1+ 7-10 and 4+ 11-13). In contrast to 1 the twofold methylsubstituted epoxy-diene 4 shows mainly (E/Z)- ...