反应详情

As in Example 99, 3,3-bis(4-chlorophenyl)-2-propenal (11.08) was reacted with (carbethoxymethylene)triphenylphosphorane (14.3 g) in ethanol (30 ml) for 30 minutes at ambient temperature. The mixture of esters obtained from the usual work up was purified by crystallization from ether-hexane to give 8.1 g of (E)-5,5-bis(4-chlorophenyl)-2,4-pentadienoic acid ethyl ester, mp 98°-100° C. A portion of the (E)-isomer was crystallized from hexane to yield the pure ester (E)-5,5-bis(4-chlorophenyl)-2,4-pentadienoic acid ethyl ester mp 98.5°-100° C.

1. customobtained from the usual work
2. customup was purified by crystallization from ether-hexane