发明授权
US4810819A 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
- 专利标题: Process for the preparation of optically active alpha-acrylalkanoic acids and novel intermediates thereof
- 专利标题(中): 制备光学活性α-丙烯酰基链烷酸的方法及其新型中间体
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申请号: US81688申请日: 1987-08-05
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公开(公告)号: US4810819A公开(公告)日: 1989-03-07
- 发明人: Claudio Giordano , Graziano Castaldi , Fulvio Uggeri , Silvia Cavicchioli
- 申请人: Claudio Giordano , Graziano Castaldi , Fulvio Uggeri , Silvia Cavicchioli
- 申请人地址: ITX Vincenza
- 专利权人: Zambon Spa
- 当前专利权人: Zambon Spa
- 当前专利权人地址: ITX Vincenza
- 主分类号: C07C45/46
- IPC分类号: C07C45/46 ; C07C49/807 ; C07C51/00 ; C07D317/32 ; C07C69/76
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.
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