Novel synthesis of butatriene derivatives by reactions of 3-bromo-3-alken-1-ynes with organocopper(I) species

Abstract

3-Bromo-3-alken-1-ynes (I) have been converted by isopropyl- and t-butylcopper into pure butatrienes (II) in an anti-SN2′-process. n-Alkylcopper species produced highly impure butatrienes, presumably because of subsequent addition of unreacted n-alkylcopper to the initially formed butatrienes. Phenylcopper did not give the SN2′-reaction with I and its homocuprate derivative also gave disappointing results.