Synthesis of monoprotected 1, 4-diketones by photoinduced alkylation of enones with 2-substituted-1, 3-dioxolanes

R Mosca, M Fagnoni, M Mella, A Albini

Index: Mosca, Raffaella; Fagnoni, Maurizio; Mella, Mariella; Albini, Angelo Tetrahedron, 2001 , vol. 57, # 52 p. 10319 - 10328

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Citation Number: 49

Abstract

Photosensitized hydrogen abstraction from 2-alkyl-1, 3-dioxolanes by triplet benzophenone gives the corresponding 1, 3-dioxolan-2-yl radicals and these are trapped by α, β-unsatured ketones yielding monoprotected 1, 4-diketones. With open chain ketones (3-buten-2-one and 4-penten-3-one) the yields are low and competitive pathways in part consume the radicals. With cyclic enones however, yields are good as tested with cyclopentenone, ...