Diallylation of 2,2-dialkylbenzodioxoles from TiCl4-mediated allylsilane reaction

Reaction of aliphatic ketones with catechol afforded 2,2-dialkylbenzodioxoles. Treatment of these benzodioxoles with allyltrimethylsilane in the presence of titanium tetrachloride led to 4,4-dialkylhepta-1,6-dienes resulting from a diallylation process. Ring-closing metathesis gave rise to 4,4-dialkylcyclopentenes.