Synthesis of gem-difluoromethylenated massoialactone by ring-closing metathesis

4,4-Difluoromassoialactone has been synthesized for the first time via a very short sequence, where the ring-closing metathesis (RCM) was employed as a key step. The efficient procedure can easily be extended to the synthesis of other gem-difluoromethylenated α,β-unsaturated-δ-lactone moiety. In addition, the viability of RCM of high electron-deficient olefins has been demonstrated.