PROCESS FOR PREPARING 2-METHOXYCARBONYLMETHYL-6,6-DIMETHYL-2- TETRAHYDROPYRAN CARBOXYLIC ACID
    90.
    发明授权
    PROCESS FOR PREPARING 2-METHOXYCARBONYLMETHYL-6,6-DIMETHYL-2- TETRAHYDROPYRAN CARBOXYLIC ACID 有权
    用于生产2-甲氧羰基甲基-6,6-二甲基-2- tetrahydropyranecarboxylic

    公开(公告)号:EP1907371B1

    公开(公告)日:2011-11-23

    申请号:EP06792504.0

    申请日:2006-07-14

    CPC分类号: C07C211/35 C07D309/08

    摘要: Process for preparing 2-methoxycarbonylmethyl-6,6-dimethyl-2-tetrahydropyran carboxylic acid (I) comprising: a) Reaction of 5-bromo-2-methyl-2-pentene (III) with magnesium and then diethyloxalate to obtain ethyl-2-oxo-6-methyl-5-heptenoate (IV); b) Reaction of ethyl-2-oxo-6-methyl-5-heptenoate (IV) with an alkali amide and methyl acetate to obtain ethyl-2- methoxycarbonylmethyl^-hydroxy-θ-methyl- 5-heptenoate (V); c) Reaction of ethyl-2- methoxycarbonylmethyl-2-hydroxy-6-methyl-5-heptenoate (V) with an alkali metal hydroxide to obtain the corresponding 2-carboxymethyl- 2-hydroxy-6-methyl-5-heptenoic acid (Vl); d) Cyclisation of 2-carboxymethyl-2-hydroxy-6-methyl-5-heptenoic acid (Vl) with formic acid to give 2-carboxymethyl-6,6-dimethyl-2-tetrahydropyrancarboxylic acid (VII); e) Monoesterification of 2-carboxymethyl-6,6-dimethyl-2- tetrahydropyrancarboxylic acid (VII) to 2-methoxycarbonylmethyl-6,6-dimethyl- 2-tetrahydropyran carboxylic acid (I), characterised in that in stage (e) the 2-methoxycarbonylmethyI-6,6-dimethyl-2- tetrahydropyran carboxylic acid (I) is purified by means of the formation of the corresponding salt with cyclohexylamine (IA).