申请人:Takasago International Corporation
公开号:US04994602A1
公开(公告)日:1991-02-19
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.
披露了一种制备光学活性6-t-丁氧基-3,5-二羟基己酸酯的方法,其化学式为:其中t-Bu代表t-丁基基团;R.sup.4代表较低的烷基基团,该方法可用作campactin、mevinolin或其类似物的内酯部分的前体,包括在存在钌-光学活性膦配合物的情况下,不对称氢化4-t-丁氧基乙酰基乙酸酯以获得光学活性4-t-丁氧基-3-羟基丁酸酯,将该酯与醋酸酯的锂烯醇酸酯反应以获得光学活性6-t-丁氧基-5-羟基-3-酮己酸酯,然后在存在钌-光学活性膦配合物作为催化剂的情况下对所得酯进行不对称氢化。所需产品可以在高立体选择性下获得良好产率。