Stepwise Cross-Couplings of a Dibromo-γ-methylenebutenolide as an Access to Z-Configured α-Alkenyl-γ-alkylidenebutenolides. Straightforward Synthesis of the Antibiotic Lissoclinolide - Sorg, Achim; Blank, Frederik; Brückner, Reinhard (Synlett, 2005)