Organocopper compounds rearrangement

When X=OH, this conversion of acetylenic alcohols to unsaturated aldehydes or ketones is called the Meyer-Schuster rearrangement The propargyl rearrangement can also go the other way that is, 1-haloalkenes, treated with organocopper compounds, give alkynes. ... 

Organocopper compounds couple readily with allyl halides under mild conditions. In some instances the reactions are reported to be vigorous. Coupling of ethynylcopper compounds with allyl halides can be effected at the ambient temperature in the presence of halide or cyanide ligands 221). Isolation of some rearranged coupling products in certain reactions 44, 66) may indicate the intermediacy of allylcopper(III) species. The reactions are summarized in Table VII. 

---