2,6,6-Trimethyl-2-cyclohexen-1-one → 2,6,6-Trimethyl-cyclohex-3-en-1-one

Participants

Reaction Steps

150 g of 2,6,6-trimethyl-cyclohex-2-en-1-one and 15 g of aluminium isopropylate were heated at 160° under argon atmosphere until obtention of a clear solution, in a reaction vessel fitted with a fractioning device. The clear mixture was then progressively heated to 190° and kept at this temperature for 60 hours, under vigorous stirring, the formed 2,6,6-trimethyl-cyclohex-3-en-1-one being directly distilled from the reaction mixture. During this period, a further amount of 300 g of starting ketone was added to the reaction mixture. 285 g of a distillate containing 40% of the desired product and 60% of unreacted starting material were thus obtained. After further distillation of the above 285 g there were finally isolated 105 g of the desired ketone having b.p. 62°/15 Torr (yield: 92%--conversion rate of 25%).

Provenance & Evidence