申请人:Firmenich SA
公开号:US05728866A1
公开(公告)日:1998-03-17
A method for preparing 3-oxo-2-pentyl-1-cyclopentaneacetic acid or methyl 3-oxo-2-pentyl-1-cyclopentaneacetate, essentially in the form of the (+)-(1R)-cis isomer thereof. The method includes the steps of (a) catalytically hydrogenating a compound of the formula (I), ##STR1## wherein M is a hydrogen atom, an alkali metal or alkaline earth metal atom, or a group NR.sub.4, where R is a hydrogen or a lower alkyl radical, in a suitable solvent and in the presence of a catalyst consisting of an Ru(II) complex comprising chiral ligands that contain a 2,2'-bis(diphenylphosphino)-1,1'-dinaphthyl (BINAP) radical or a 1,2-bis(2,5-dialkylphospholano)benzyl (DuPHOS) radical, wherein the alkyl is a C.sub.2 or C.sub.3 radical, to give a compound of formula (II), ##STR2## wherein M has the meaning given above, essentially in the form of the (+)-(1R)-cis isomer thereof; (b) if required, acidifying, in a per se known manner, the compound of formula (II), wherein M is an alkali metal or alkaline earth metal atom, or a group N.sub.4, where R is hydrogen or a lower alkyl radical, to give (+)-(1R)-cis-3-oxo-2-pentyl-1-cyclopentaneacetic acid; and (c) if required, esterifying the resulting (+)-(1R)-cis-3-oxo-2-pentyl-1-cyclopentaneacetic acid under suitable conditions to form methyl (+)-(1R)-cis-3-oxo-2-pentyl-1-cyclopentaneacetate.
一种制备3-氧代-2-戊基-1-环戊基乙酸或甲基3-氧代-2-戊基-1-环戊基乙酸酯的方法,基本上以其(+)-(1R)-顺式异构体的形式存在。该方法包括以下步骤:(a)在适当的溶剂中,在催化氢化剂的存在下,催化氢化具有如下式(I)的化合物,其中M是氢原子、碱金属或碱土金属原子,或基团NR.sub.4,其中R是氢或较低烷基基团,所述催化剂由含有2,2'-双(二苯基膦基)-1,1'-二萘基(BINAP)基团或1,2-双(2,5-二烷基膦烷基)苯基(DuPHOS)基团的手性配体的Ru(II)配合物组成,其中烷基是C.sub.2或C.sub.3基团,以得到具有如下式(II)的化合物,其中M具有上述给定的含义,基本上以其(+)-(1R)-顺式异构体的形式存在;(b)如有必要,按照已知的方法,使式(II)的化合物酸化,其中M是碱金属或碱土金属原子,或基团N.sub.4,其中R是氢或较低烷基基团,以得到(+)-(1R)-顺式-3-氧代-2-戊基-1-环戊基乙酸;以及(c)如有必要,在适当条件下对所得的(+)-(1R)-顺式-3-氧代-2-戊基-1-环戊基乙酸酯化,形成甲基(+)-(1R)-顺式-3-氧代-2-戊基-1-环戊基乙酸酯。