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    Process for the preparation of optically active alpha-acrylalkanoic acids and novel intermediates thereof
    5.
    发明授权
    Process for the preparation of optically active alpha-acrylalkanoic acids and novel intermediates thereof 失效
    制备光学活性α-丙烯酰基链烷酸的方法及其新型中间体

    公开(公告)号：US4810819A

    公开(公告)日：1989-03-07

    申请号：US81688

    申请日：1987-08-05

    申请人： Claudio Giordano ,  Graziano Castaldi ,  Fulvio Uggeri ,  Silvia Cavicchioli

    发明人： Claudio Giordano ,  Graziano Castaldi ,  Fulvio Uggeri ,  Silvia Cavicchioli

    IPC分类号： C07C45/46 ,  C07C49/807 ,  C07C51/00 ,  C07D317/32 ,  C07C69/76

    CPC分类号： C07D317/32 ,  C07C45/46 ,  C07C49/807 ,  C07C51/00

    摘要： A new enantioselective process is described for preparing optically active alpha-arylalkanoic acids by:(a) halogenation on the aliphatic carbon atom alpha to the ketal group, of ketals of formula ##STR1## in which Ar represents an aryl, optionally substituted;R represents a C.sub.1 -C.sub.4 alkyl;R.sub.1 and R.sub.2, represents a hydroxy, a O.sup.- M.sup.+, OR.sub.3 or NR.sub.4 R.sub.5 group;the carbon atoms indicated by an asterisk both simultaneously are in (R) or (S) configuration. This reaction is diastereoselective, so that a mixture of alpha-haloketals is obtained in which one of the two epimers prevails, and generally strongly prevails, over the other.(b) rearrangement of the haloketals of formula ##STR2## in which X is Cl, Br or I to alpha-arylalkanoic acids in a single stage or in two successive stages, by way of esters of formula ##STR3## The compounds (A) and (C) are all new compounds. The rearrangement step (b) may be performed under new, inventive conditions.The esters of formula (C) have pharmacological activity analogous to that of the corresponding alpha-arylalkanoic acids.

    摘要翻译： 描述了通过以下方法制备光学活性α-芳基链烷酸的新的对映选择性方法：（a）在缩酮的α-脂肪族碳原子上卤化式（ⅠA）的缩酮，其中Ar表示任选取代的芳基; R代表C1-C4烷基; R1和R2表示羟基，O-M +，OR3或NR4R5基团; 由星号表示的碳原子同时为（R）或（S）构型。 该反应是非对映选择性的，因此获得了α-二酮的混合物，其中两个差向异构体中的一个占优势，并且通常强大地占优势。 （b）通过式（IMA）的（C）（C）的酯，将单体或两个连续阶段中的X为Cl，Br或I的式（A）所示的配子重新排列成α-芳基链烷酸 ）化合物（A）和（C）都是新的化合物。 重新布置步骤（b）可以在新的创造条件下进行。 式（C）的酯具有类似于相应的α-芳基链烷酸的药理活性。