PROCESS FOR PREPARING PENTENOATE

The invention pertains to a process for preparing a compound of formula (1), wherein R1 is independently chosen from C1-C6 alkyl, cycloalkyl, aralkyl and aryl, and R2, R3 and R4 are independently chosen from hydrogen and C1-C6 alkyl, cycloalkyl, aralkyl and aryl; which process comprises the steps of: a) contacting a compound of formula (2), wherein R1 and R2 are as above and M+ is a monovalent metal ion, with a compound of formula (3), wherein R3 and R4 are as above, to form a compound of formula (4); and b) followed by contacting the compound of formula (4) with an acid to give a compound offormula (1), wherein step (a) and/or step (b) are conducted in continuous mode. 本发明涉及一种制备式(1)化合物的方法其中R独立地选自C-C烷基、环烷基、芳烷基和芳基，且R、R和R独立地选自氢和C-C烷基、环烷基、芳烷基和芳基；所述方法包含以下步骤：a)使式(2)化合物其中R和R如上，且M为单价金属离子，与式(3)化合物接触其中R和R如上，以形成式(4)化合物和b)随后使所述式(4)化合物与酸接触以得到式(1)化合物，其中步骤(a)和/或步骤(b)以连续模式进行。