δ-酮酸的酯化反应

Esterification ofδ-Ketonic Acids

本文采用一元酮与丙烯腈在氢氧化钾的乙二醇溶液催化下,合成了δ-酮腈,经水解得到的酮酸在固体硫酸铁水合物催化下加热合成了不饱合环内酯,而酮酸又分别同甲醇、乙醇、丁醇在硫酸铁水合物催化下反应得到了相应的羧酸酯(X)—(Ⅻ),产率为48—88%.

3-(β-cyanoethyl)-2-butanone(Ⅰ),2-(β-cyanoethyl)-cyclohexanone(Ⅱ)and 2-(β-cyanoethyl)-acetophenone(Ⅲ)have been prepared by treating 2-butanone,cyclohexanone and acetophenone respectively with acrylonitrile in the presence of KOH/ethylene glycoi,and converted to correspondingδ-Keto-acids by reflux with dil.HC1.When theseδ-Ke-tonic acids are refluxed with ferric sulfate hydrate three unsaturated.lactones that 5,6-dimethyl-3,4-dihydro-a-pyrone,△9,10-hexahydrocoumarin and 6-phenyl-3,4-dihydro-a-pyrone are obtained in yields of 77.8,86.7 and 29%respectively.Moreover,the(3-Keto-acids above react with alcohols(mothanol,ethanol or butanol)by using hydrated ferric sulfate as catalyst to give(3-Keto-esters in 48-88%yields.