Diethyl Malonate → 5-(2,3-Dihydro-2,2,4,5,6-pentamethylbenzofuran-7-yl)cyclohexane-1,3-dione

Participants

Reaction Steps

To a solution of 1.57 g of sodium in 68 ml of absolute methanol was added 10.35 ml of diethyl malonate. After stirring for 20 minutes, the mixture was added 8 g of the 4-(2,3-dihydro-2,2,4,5,6-pentamethylbenzofuran-7-yl)-3-buten-2-one in 17.5 g of absolute methanol, refluxed for 4 hours and added 150 g of 5% aqueous solution of sodium hydroxide. The reaction mixture was cooled to room temperature and washed three times with 50 ml of diethyl ether. 2N aqueous solution of hydrochloric acid was added dropwise into the aqueous layer until the bubble of carbon dioxide ceased. And then, solid was dissolved in ethyl acetate and washed with water. The combined organic layer was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to afford 16.7 g of 5-(2,3-dihydro-2,2,4,5,6-pentamethyl-benzofuran-7-yl)cyclohexane-1,3-dione as a yellow solid.

Provenance & Evidence