Abstract Biologically active ynenol lactones 1 are stereospecifically obtained when acetylenic carboxylates are reacted with 1-bromo 1-alkynes in the presence of a palladium (O)-phosphine complex. The reaction is effective only with the potassium carboxylate and the nature of the phosphine is essential for the cyclisation process.
[Spencer, Robin W.; Tam, Tim Fat; Thomas, Everton; Robinson, Valerie J.; Krantz, Allen Journal of the American Chemical Society, 1986 , vol. 108, # 18 p. 5589 - 5597]
