Triethyl phosphonoacetate → ethyl-E-4-(3-methoxyphenyl)-4-methylpent-2-enoate

Participants

Reaction Steps

33.6 g (114.3 mmol) of phosphonoacetic acid triethyl ester is introduced into 148 ml of tetrahydrofuran. At 0° C., 79.7 ml of a 2 M solution of LDA in THF/heptane/ethylbenzene is added in drops (one and one-half hours). After one hour of stirring, 24.3 g (136.34 mmol) of 2-(3-methoxyphenyl)-2-methylpropanal, dissolved in 130 ml of tetrahydrofuran, is added in drops at 0° C. After five days of stirring at room temperature, the reaction mixture is poured onto 250 ml of dilute ammonium chloride solution and extracted twice with 400 ml each of diethyl ether. The combined organic extracts are treated as usual, and the residue that is obtained is chromatographed on silica gel (mobile solvent: ethyl acetate/hexane). 27.2 g (80.4%) of the desired compound is isolated.

Provenance & Evidence