Water → 6-(But-3-en-1-yl)-3-ethoxycyclohex-2-en-1-one

Participants

Reaction Steps

A solution of 25 g. (0.178 mole) of 3-ethoxy-2-cyclohexen-1-one in 25 ml. of tetrahydrofuran was added dropwise over a 30 minute period to a -78° C. solution of 0.196 mole of lithium diisopropylamide (from 27.4 ml., 0.196 mole, of diisopropylamine and 85 ml., 0.187 moles of 2.2 M n-butyllithium in hexane) in 125 ml. of tetrahydrofuran. The reaction was then stirred for 30 minutes and 65 ml. (0.374 mole) of hexamethylphosphoramide added followed by 38.9 ml. (0.383 mole) of 4-bromo-1-butene. The reaction was then allowed to warm to room temperature, stirred for 1.5 hours and then quenched by addition of 5 ml. (0.277 mole) of water. Most of the solvent was removed on a rotovapor and the residue diluted with 1000 ml. ice water and 500 ml. ether. The ether phase was separated, washed with two 300 ml. portions of water, dried over magnesium sulfate and evaporated on a rotovapor. Distillation of the resulting crude oil gave 10.1 g. (29%) of the title product.

Provenance & Evidence