In this paper, it was found that isopropylidene (1-hydroxy-3-oxo-butylidene) malonate 4 was a heat unstable compound and the one step convenient methods for preparation of 4-hydroxy-6-methyl-2-pyrone 1 and 3-carboxy-4...In this paper, it was found that isopropylidene (1-hydroxy-3-oxo-butylidene) malonate 4 was a heat unstable compound and the one step convenient methods for preparation of 4-hydroxy-6-methyl-2-pyrone 1 and 3-carboxy-4-hydroxy-6-methyl-2-pyrone 2 in good yields were reported. Isopropylidene malonate 3、diketen and triethylamine reacted in chloroform to give 2, and in the mixture of dichloromethane and chlorobenzene to offer 1.展开更多
化学杀雄剂(Chemical induction agent of male sterility)又名化学杂交剂(Chemicalhybridizing agent)、杀雄配子剂(Male gametocide),雄性不育剂(Male sterilant)、花粉抑制剂(Pellen suppressant)等等。化学杀雄是培育杂种的一种有...化学杀雄剂(Chemical induction agent of male sterility)又名化学杂交剂(Chemicalhybridizing agent)、杀雄配子剂(Male gametocide),雄性不育剂(Male sterilant)、花粉抑制剂(Pellen suppressant)等等。化学杀雄是培育杂种的一种有效方法,它能够直接杀伤或抑制植物的雄性器官的生活力,从而造成生理上的不育,达到了去雄的目的。展开更多
文摘In this paper, it was found that isopropylidene (1-hydroxy-3-oxo-butylidene) malonate 4 was a heat unstable compound and the one step convenient methods for preparation of 4-hydroxy-6-methyl-2-pyrone 1 and 3-carboxy-4-hydroxy-6-methyl-2-pyrone 2 in good yields were reported. Isopropylidene malonate 3、diketen and triethylamine reacted in chloroform to give 2, and in the mixture of dichloromethane and chlorobenzene to offer 1.
文摘化学杀雄剂(Chemical induction agent of male sterility)又名化学杂交剂(Chemicalhybridizing agent)、杀雄配子剂(Male gametocide),雄性不育剂(Male sterilant)、花粉抑制剂(Pellen suppressant)等等。化学杀雄是培育杂种的一种有效方法,它能够直接杀伤或抑制植物的雄性器官的生活力,从而造成生理上的不育,达到了去雄的目的。