在H3PO4存在下2,3-二甲基-2-丁烯与乙酐的酰化反应

在H3PO4存在下进行了2，3－二甲基－2－丁烯与乙酐的酰化反应，结果表明，H3PO4是室温下催化2，3－二甲基－2－丁烯与乙酐酰化反应的有效催化剂，在H3PO4存在下，酰化产物的收率主要取决于：（a)H3PO4的用量，（b)乙酐的用量；（c)反应温度和（d)反应时间，在适宜反应条件下，所得3，3，4－三甲基－4－戊烯－2－酮（TMP）约为99％，另外还发现，反应体系中加入少量乙酸，不会明显减少酰化产物的收率，乙酐的纯度，反应物的加入顺序对该反应几乎没有任何影响，在有和没有溶剂CH2Cl2的条件下所得酰化产物的收率是可比的。

Acylation of 2,3-Dimethyl-2-butene by Acetic Anhydride in the Presence of H3PO4

The acylation of 2,3-dimethyl-2-butene by acetic anhydride in the presence of H3PO4 was investigated.It was found that H3PO4 is an effective catalyst for the acylation of 2,3-dimethyl-2-butene by acetic anhydride at room temperature.The yield of the acylated product obtained in the presence of H3PO4 depends mainly upon:(a) the amount of H3PO4 used; (b) the amount of acetic anhydride used; (c) reaction temperature and (d) reaction time.Under appropriate reaction conditions the best yield of 3,3,4-trimethyl-4-penten-2-one (TMP) obtained is about 99%.In addition,we found that the addition of a small amount of acetic acid to the reaction system did not significantly decrease the yield of the acylated product.The purity of acetic anhydride has scarcely any influence on the reaction.The order of the addition of reactants has also scarcely any effect on the reaction.The yields obtained in the presence and absence of solvent CH2Cl2 are comparable.