Synthesis, Stability, and Diels‐Alder Reactions of Methyl 2‐Oxobut‐3‐enoate

Abstract

Methyl vinyl glycolate (MVG, methyl 2‐hydroxybut‐3‐enoate) is a new biobased platform chemical, which is available by degradation of carbohydrates. In the present work, the oxidation of MVG to methyl 2‐oxobut‐3‐enoate has been investigated and a procedure developed with the Dess‐Martin periodinane. Methyl 2‐oxobut‐3‐enoate has not been characterized before and is stable for days at −18 °C, but slowly dimerizes by an unusual hetero‐Diels‐Alder reaction at room temperature. Therefore, the reactivity of methyl 2‐oxobut‐3‐enoate in the normal Diels‐Alder reaction with 1,3‐dienes has been investigated and a one‐pot procedure developed where MVG is first oxidized with the Dess‐Martin periodinane followed by the addition of the 1,3‐diene. A number of different 1,3‐dienes can take part in the cycloaddition to afford the functionalized cyclohexene products in moderate‐to‐good yields.