Carboxylate-Directed Tandem Functionalisations of α,β-Dihaloalkenoic Acids with 1-Alkynes: A Straightforward Access to (Z)-Configured, α,β-Substituted γ-Alkylidenebutenolides
and stereoselectively leads to rarely described (Z)‐3‐halo‐5‐ylidene‐5H‐furan‐2‐ones. These compounds are subsequently able to undergo classical Pd‐catalysed cross‐coupling reactions, providing 3‐substituted and 3,4‐disubstituted 5‐ylidene‐5H‐furan‐2‐ones (see scheme).