Route to Substituted Furan-2(5H)-ones from cyclo-Alkenecarboxylic Acids and Acrylates via C-H Activation.

Under rhodium(III) catalysis, four kinds of cycloalkenecarboxylic acids successfully reacted with acrylates via direct activation of the β-alkenyl C-H bond. The present protocol provides the facile and highly efficient synthesis of substituted furan-2(5H)-ones from readily available starting materials with moderate to good yields. In addition, their possible reaction mechanisms were also discussed.