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69 条记录 (耗时 0.032 秒)

    Process for preparing optically active 6-t-butyoxy-3,5-dihydroxyhexanoic esters
    16.
    发明授权
    Process for preparing optically active 6-t-butyoxy-3,5-dihydroxyhexanoic esters 失效
    光学活性6-叔丁氧基-3,5-二羟基己酸酯的制备方法

    公开(公告)号：US4994602A

    公开(公告)日：1991-02-19

    申请号：US485692

    申请日：1990-02-27

    申请人： Nobuo Seido ,  Noboru Sayo ,  Hidenori Kumobayashi

    发明人： Nobuo Seido ,  Noboru Sayo ,  Hidenori Kumobayashi

    IPC分类号： C07C67/31 ,  C07C69/708

    CPC分类号： C07C67/31 ,  C07C69/708

    摘要： A process for preparing an optically active 6-t-butoxy-3,5-dihydroxyhexanoic ester represented by formula: ##STR1## wherein t-Bu represents a t-butyl group; and R.sup.4 represents a lower alkyl group, which is useful as a precursor of a lactone moiety of campactin, mevinolin or analogues thereof is disclosed, comprising asymmetrically hydrogenating a 4-t-butoxyacetoacetic ester in the presence of a ruthenium-optically active phosphine complex to obtain an optically active 4-t-butyoxy-3-hydroxybutanoic ester, reacting the ester with a lithium enolate of an acetic ester to obtain an optically active 6-t-butyoxy-5-hydroxy-3-oxohexanoic ester, and asymmetrically hydrogenating the resulting ester in the presence of a ruthenium-optically active phosphine complex as a catalyst. The desired product can be obtained in good yield at high stereoselectivity.

    Process for producing optically active alpha-hydroxycarboxylates
    19.
    发明授权
    Process for producing optically active alpha-hydroxycarboxylates 失效
    光学活性α-羟基羧酸盐的制备方法

    公开(公告)号：US4965398A

    公开(公告)日：1990-10-23

    申请号：US386480

    申请日：1989-07-28

    申请人： Koichi Mikami ,  Masahiro Terada ,  Takeshi Nakai ,  Noboru Sayo ,  Hidenori Kumobayashi

    发明人： Koichi Mikami ,  Masahiro Terada ,  Takeshi Nakai ,  Noboru Sayo ,  Hidenori Kumobayashi

    IPC分类号： B01J31/22 ,  C07B61/00 ,  C07C67/347 ,  C07C69/732

    CPC分类号： C07C69/732

    摘要： A process for preparing an .alpha.-hydroxycarboxylate represented by formula (I): ##STR1## wherein R.sup.1 represents a hydrogen atom or a lower alkyl group; R.sup.2 represents a lower alkyl group, a phenyl group or a cycloalkyl group, or R.sup.1 and R.sup.2 are bonded to each other to form a five- to seven-membered cycloalkenyl or bicycloalkenyl ring which may be substituted with a lower alkyl group; and R.sup.3 represents a lower alkyl group,which comprises reacting an olefin compound represented by formula (II): ##STR2## wherein R.sup.1 ' represents a hydrogen atom or a lower alkyl group; and R.sup.2 ' represents a lower alkyl group, a phenyl group or a cycloalkyl group, or R.sup.1 ' and R.sup.2 ' are bonded to each other to form a five- to seven-membered cycloalkyl or bicycloalkyl ring which may be substituted with a lower alkyl group,with a glyoxylate represented by formula (III): ##STR3## wherein R.sup.3 is as defined above, in the presence of a binaphthol-titanium complex represented by formula (IV): ##STR4## wherein X represents a chlorine atom or bromine atom.