A method of synthesis of para-substituted benzoate esters and acids is provided, wherein the para-substituted regioisomer is obtained substantially free of the meta-substituted impurity, the method comprising contacting a coumalate ester or acid and an un activated alkene at elevated temperature in the presence of a metal oxidation catalyst and an oxidant. The metal oxidation catalyst can be palladium, such as palladium on carbon, and the oxidant can be the oxygen gas in ambient air. The reaction can be carlied out without solvent or in high boiling hydrocarbon solvents such as mesitylene. When the un activated alkene is a monosubstituted alkene, yields of at least about 50 or 60% of para-substituted ester and acid products, respectively, are obtained, substantially free of the regioisomelic meta-substituted impurity.
                            提供一种合成对位取代
苯甲酸酯和酸的方法,其中对位取代异构体在实质上不含有间位取代杂质,该方法包括在高温下在
金属氧化催化剂和氧化剂的存在下,使
香豆酸酯或酸与非活化烯烃接触。
金属氧化催化剂可以是
钯,如碳上的
钯,氧化剂可以是环境空气中的
氧气。反应可以在无溶剂条件下进行,或者在高沸点的碳氢化合物溶剂中进行,如
甲苯。当非活化烯烃是单取代烯烃时,可以获得至少约50%或60%的对位取代酯和酸产品收率,且这些产品在实质上不含有异构体间位取代杂质。