Regioselective Alkynylation of Allylic Phosphates with Alkynyl Copper Reagents.

We developed an alkynylation of allylic phosphates with acetylenes in the presence of copper and magnesium salts. The reaction proceeded regioselectively to afford the corresponding 1,4‐enynes. Furthermore, the functional group tolerance of this reaction was established. As an application, the 1,4‐enyne intermediate involved in the synthesis of 13R,19S,20S‐trihydroxydocosapentaenoic acid could be efficiently synthesized. [ABSTRACT FROM AUTHOR]