Heck reaction with 3-fluoro-3-buten-2-one

3-Fluoro-3-buten-2-one (2) is readily prepared from 1-fluoro-1-chloro-2-methoxy-2-methylcyclopropane (1) in 82% yield by heating the cyclopropane in aqueous quinoline solution. Ketone 2 reacts with aryl iodides (3) in a Heck reaction catalyzed by Pd(OAc)2 to give Z-3-fluorobenzalacetones (4) in 36–86% yield.