Solvent-dependent reactivities of acyclic nitrones with β-diketones: catalyst-free syntheses of endiones and enones

J Lasri, G Gajewski, MFCG da Silva, ML Kuznetsov…

Index: Lasri, Jamal; Gajewski, Grzegorz; Guedes Da Silva, M. Fatima C.; Kuznetsov, Maxim L.; Fernandes, Ricardo R.; Pombeiro, Armando J.L. Tetrahedron, 2012 , vol. 68, # 35 p. 7019 - 7027

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Citation Number: 6

Abstract

Reactions of the nitrones− O+ N (Me) C (H) Ar 1 (Ar= phenyl 1a, 4-methylphenyl 1b, 2, 4, 6- trimethylphenyl 1c, and anthracen-9-yl 1d) with the cyclic β-diketones 1, 3-indandione 2 or barbituric acid 3 in CH2Cl2, afford the corresponding endiones 2′ a–2′ d or 3′ a–3′ d. In contrast, dimedone 4 reacts with 1a or 1b to give the endione 4′ a or 4′ b and the bis- adduct 4 ″a or 4 ″b. Nevertheless, reaction of 4 with 1c or 1d in CH2Cl2 furnishes only ...