Acetoacetic esters of the formula R--OOCCH.sub.2 COCH.sub.3 are reacted with an unsaturated ester of the formula R.sup.1 R.sup.2 C.dbd.CHCOOR.sup.3 in the presence of basic catalyst such as ethanolic sodium ethoxide to give compound I of the formula ##STR1## and the alcohol by-product HOR.sup.3. By known hydrolysis and decarboxylation procedures, compound I is convertible to compound II of the formula ##STR2## In the above formulas, R is alkyl, R.sup.1 and R.sup.2 are each selected independently from H, alkyl, alkylthioalkyl, cycloalkyl, alkyl substituted cycloalkyl, aryl, substituted aryl, heterocyclic, or substituted heterocyclic, and R.sup.3 is alkyl or cycloalkyl. These compounds I and II are intermediates in the preparation of known herbicides.
式为R--OOCCH.sub.2 COCH.sub.3的
乙酰乙酸酯与式为R.sup.1 R.sup.2 C.dbd.CHCOOR.sup.3的不饱和酯在碱性催化剂(例如
乙醇钠乙酸盐)存在下反应,生成式为##STR1##的化合物I和醇副产物HOR.sup.3。通过已知的
水解和脱羧程序,化合物I可转化为式为##STR2##的化合物II。在上述公式中,R为烷基,R.sup.1和R.sup.2各自独立地选择自H、烷基、烷基
硫代烷基、环烷基、取代的环烷基、芳基、取代的芳基、杂环或取代的杂环,而R.sup.3为烷基或环烷基。这些化合物I和II是已知
除草剂制备中的中间体。