Acetic acid, 2-(triphenylphosphoranylidene)-, ethyl ester → HCID 14196833, compound

Participants

Reaction Steps

A solution of 3,3-diphenyl-2-propenal (18.73 g) and (carbethoxymethylene)triphenylphosphorane (33.1 g) in ethanol (100 mL) was stirred at room temperature for 1 hour. The solvent was removed in vacuo and the residual solid was refluxed in a mixture of ether (125 mL) and hexane (250 mL) for 10 minutes. The mixture was cooled to room temperature and the precipitated triphenylphosphine oxide (25 g) was removed by filtration and was washed with ether-hexane (1:2; 2×50 mL). The filtrates were evaporated and the residue was passed through a short column of silica gel (200 g) made up in dichloromethane to remove residual triphenylphosphine oxide and starting ylid. After evaporation of the appropriate eluates, the resulting mixture of esters was separated by using HPLC (dichloromethane-hexane; 1:1). The fractions containing the less polar material were combined and evaporated to yield 4.2 g of (Z)-5,5-diphenyl-2,4-pentadienoic acid ethyl ester as an oil which crystallized on standing, mp 36°-37° C.

Provenance & Evidence