Síntesis, Reactividad y Aplicaciones Sintéticas de Dienos y Heterodienos de 1,3-Oxazolidin-2-onas

Abstract

This paper describes the significant role that the exo-diene oxazolidin-2-ones 3-4 play as building blocks for the construction of more complex molecules with potential use for the preparation of biological active compounds. Thus, the oxidation of dienes 3-4 using MCPBA promoted the formation of 1,3-oxazolidin-2,4-diones 5-6, which have an interesting α,β-unsaturated fragment. The functionalization of the beta-position of these compounds was carried out via nucleophilic Michael-type additions furnishing adducts 7-16, which are direct precursors of alphahidroxiamidas. The functionalization of dienes exo-oxazolidin-2-ones 3-4 by a Vilsmeier-Haack reaction led to a new class of dienes 17, incorporating a formyl group at the methylene carbon C-4. These new compounds were evaluated in the Baylis-Hillman reaction to functionalize the alpha-carbon to the formyl group, giving adducts 18, which have an attractive structure because exhibit both electrophilic and nucleophilic reactivity regions. In addition, this Baylis-Hillman reaction is a quite novel reaction, since it took place in a conjugated double vinylogous framework.