The present invention relates to a novel method for producing cyclopentenolone of the formula (I), ##STR1## which is a useful intermediate for producing agricultural chemicals, which comprises reacting an acetonedicarboxylic ester of the formula (VII), ##STR2## wherein R is a C.sub.1 -C.sub.6 alkyl group, with 2-propynyl chloride in the presence of magnesium alkoxide and in the presence of alkali iodide to obtain novel mono-(2-propynyl)-substituted acetonedicarboxylic ester of the formula (VI), ##STR3## wherein R is as defined above; hydrolyzing the mono-(2-propynyl)-substituted acetonedicarboxylic ester of the formula (VI) under alkaline conditions with an alkali and then reacting the hydrolyzed product with methylglyoxal of the formula, ##STR4## to obtain novel .gamma.-diketone of the formula (V), ##STR5## and ring-closing the .gamma.-diketone of the formula (V) under alkaline condition.
本发明涉及一种生产
环戊烯酮的新方法,该
环戊烯酮的
化学式为(I),##STR1## 该化合物是生产农业
化学品的有用中间体,包括在
镁烷氧化物和
碘化碱的存在下,将
化学式为(VII)的
丙酮二
羧酸酯与2-
丙炔基
氯反应,其中R为C.sub.1-C.sub.6烷基基团,从而获得新的单(2-
丙炔基)取代的
丙酮二
羧酸酯的
化学式为(VI),##STR3## 其中R如上所定义;在碱性条件下用碱
水解单(2-
丙炔基)取代的
丙酮二
羧酸酯的
化学式为(VI),然后与
化学式为的
甲基乙二醛反应,以获得新的γ-二酮的
化学式为(V),##STR5## 然后在碱性条件下环合γ-二酮的
化学式为(V)。