| 摘要 |
PURPOSE:To obtain in high yield the subject compound including new compound, having carcinostatic activity, by bringing a carbonic ester of a specific alka-2- yne-4-ene-1-ol into contact with a platinum metal compound catalyst under CO pressure in the presence of an alcohol. CONSTITUTION:The objective compound, a 4-oxo-5-alkylidene-2- cyclopentenecarboxylic acid derivative of formula II, can be obtained by bringing a carbonic ester of an alka-2-yne-4-ene-1-ol of formula I [R<1>-R<3> are each H or (substituted) hydrocarbon; R' is (substituted) hydrocarbon] into contact with a platinum metal compound catalyst under carbon monoxide pressure in the presence of an alcohol. The compound of the formula I can be prepared by the following process: the diol portion of a 2,3-dihydroxybutyric alkyl ester is protected with acetone followed by reduction with diisobutylaluminum hydride to introduce formyl group into the ester, and ethynyl group is added to the ester using a Grignard reagent followed by adding isopropenyl group to the end of the ethynyl group by a conventional method to extend the side chain followed by reaction of an acid chloride to convert the hydroxyl group into carbonic ester group. |
