Alkyne zipper reaction

The alkyne zipper reaction is an organic reaction which isomerizes an organic compound containing an internal alkyne into a terminal alkyne. This was first reported by Charles Allen Brown and Ayako Yamashita in 1975. The isomerization reaction proceeds for straight-chain alkynes and acetylinic alcohols and provides a useful approach for remote functionalization in long-chain hydrocarbons.

The reaction requires a strong base. The base used by Brown and Yamashita was potassium 1,3-diaminopropanide, generated in situ by adding potassium hydride to the solvent 1,3-diaminopropane. Alternative approaches have been investigated due to the expensive and hazardous nature of potassium hydride; ethylenediamine has been found to be an unsuitable replacement for 1,3-diaminopropane. As an example, for the synthesis of 9-decyn-1-ol from 2-decyn-1-ol, the lithium salt of 1,3-diaminopropane in the presence of potassium tert-butoxide affords yields of approximately 85%.