Triethyl phosphonoacetate → 5-(2,4-Dichlorophenyl)-4-methylpenta-2,4-dienoic acid ethyl ester

Participants

Reaction Steps

Sodium hydride (4.88 g of a 60% dispersion in mineral oil, 1.5 eq, 0.122 mol) was suspended in THF (442 mL). To this suspension was added a solution of diethoxyphosphorylactic acid ethyl ester (27.5 g, 0.122 mol, 1.5 eq) in THF (10 mL), dropwise. After 10 minutes a solution of 3-(2,4-dichlorophenyl)-2-methylpropenal (17.56 g, 0.082 mol) in THF (50 mL) was added, dropwise. After stirring for 4 hours the mixture was added to NH4Cl(sat) and extracted with EtOAc. The combined organic extracts were dried (MgSO4), concentrated under reduced pressure to give a residue that was purified by silica gel chromatography (0-2.5-5% EtOAc in hexanes) to give 20.9 g of 5-(2,4-dichlorophenyl)-4-methylpenta-2,4-dienoic acid ethyl ester.

Provenance & Evidence