ALTERNATIVE AND COMPLEMENTARY SYNTHETIC APPROACHES TO β CARBOXY-α-METHYLENE-γ-BUTYROLACTONE ETHYL ESTERS<br/> STRATÉGIES DE SYNTHÈSE ALTERNATIVES POUR L'ÉCHAFAUDAGE D'ESTERS ÉTHYLIQUES DE β CARBOXY-α-MÉTHYLÈNE-γ-BUTYROLACTONES

Abstract

Alternative synthetic approaches to a variety of β substituted and carboxylated α-methylene-γ-butyrolactones have been developed. In the first approach the mandatory methylene unit was incorporated on precursor compounds at early stage of the synthesis on reliance with Horner-Emmons protocol. In the alternative approach which further tolerates multifarious substituents at γ-position of the lactone template the unsaturated moiety α to the lactone carbonyl group is connected at a later stage through a deprotonation / methoxymethylation / elimination sequence.

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