Rearrangement acetylide ions

As reported recently [40], the application of carbon nucleophiles such as acetylide ions proceeds entirely via dienone-phenol rearrangement pathway. Thus, a THF solution of the appropriate acetylide was added to a solution of... 

McLafferty, Fred Warren, 732 McLafferty rearrangement. 416, 732 Mechanism (reaction), 139 acetal formation, 717-718 acetylide alkylation, 272 acid chloride formal ion with SOCl2, 795... 

Huynh and Linestrumelle then kept 11 in the presence of hexamethylphosphoramide at -75 °C, and showed that it rearranged to the allenic lithium compound 14. They suggest the reaction takes place through an ion pair. It is not clear whether or not the reaction is reversible, since the lithium allene is thermodynamically stable, though it has been claimed that the rearrangement of a lithium allene to a lithium acetylide is a forbidden concerted process. 

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