(Z)-2,2-Dimethyl-5-carboxymethylene-1,3-dioxolan-4-one: a new synthon for the synthesis of α,γ-diketoacid derivatives

The synthesis and reactivity of (Z)-2,2-dimethyl-5-carboxymethylene-1,3-dioxolan-4-one, a new and versatile synthon useful for the synthesis of selectively protected α,γ-diketoacid derivatives, are described. This new, protected form of hydroxyl fumaric acid along with its acid chloride was used to prepare ester, amide, and aryl derivatives. The dioxolane moiety was found to be a convenient functionality that facilitated ready unmasking by straightforward hydrolysis to reveal α,γ-diketoacid derivatives or derivatization to yield ester, amide, and 2,3-pyrrolidinedione derivatives.