Brønsted acid-mediated Nazarov cyclization of vinylallenes

J Org Chem. 2010 Aug 6;75(15):5410-3. doi: 10.1021/jo101112t.

Abstract

Treatment of siloxy enynes with base leads to the corresponding vinylsiloxyallenes which undergo Nazarov cyclization in the presence of trifluoroacetic acid to provide the cyclized product as a mixture of regioisomers in moderate to good overall yield.