3-hydroxy gamma-lactone based enantioselective synthesis of azetidinones
    14.
    发明授权
    3-hydroxy gamma-lactone based enantioselective synthesis of azetidinones 失效
    基于3-羟基γ-内酯的对映选择性合成氮杂环丁酮

    公开(公告)号:US5886171A

    公开(公告)日:1999-03-23

    申请号:US864529

    申请日:1997-05-28

    IPC分类号: C07D205/08

    CPC分类号: C07D205/08

    摘要: The invention relates to a process for producing a compound of the formula ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 are as defined in the specification, which comprises the steps of: (a) reacting a lactone with an imine to obtain a chiral diol of the formula IV; (b) oxidizing the diol to obtain an aldehyde of formula V; (c) condensing the aldehyde with an enolether followed by dehydration to obtain a compound of formula VI; (d) hydrogenating the compound of formula VI to obtain a ketone of formula VII; and (e) chirally catalytically reducing the ketone, wherein steps (b)-(d) are shown in the following reaction scheme: ##STR2##

    摘要翻译: 本发明涉及一种制备下式化合物的方法,其中R 1,R 2和R 3如说明书中所定义,其包括以下步骤:(a)使内酯与亚胺反应,得到手性二醇 公式IV; (b)氧化二醇以获得式V的醛; (c)将醛与烯醇缩合,然后脱水得到式VI化合物; (d)使式Ⅵ化合物氢化得到式Ⅶ的酮; 和(e)手性催化还原酮,其中步骤(b) - (d)显示在以下反应方案中:

    Process for preparing florfenicol, its analogs and oxazoline
intermediates thereto
    15.
    发明授权
    Process for preparing florfenicol, its analogs and oxazoline intermediates thereto 失效
    制备氟苯尼考,其类似物和恶唑啉中间体的方法

    公开(公告)号:US5382673A

    公开(公告)日:1995-01-17

    申请号:US39450

    申请日:1993-04-22

    CPC分类号: C07D263/10 C07C317/32

    摘要: A process for preparing a compound of formula (IV): ##STR1## comprising a) contacting an oxazoline compound of formula (I): ##STR2## wherein Z is as defined hereinbefore, with a reagent capable of causing an equilibrium between oxazoline compound (I) and an oxazoline compound of formula (II) described herein, and the reagent drives the equilibrium toward oxazoline compound (II) by preferential precipitation of oxazoline compound (II);b) contacting compound (II) with a fluorinating agent to give a fluorinated oxazoline compound of formula (III) described herein; andc) hydrolyzing the compound of formula (III) to formula (IV). In an alternative embodiment, the process is directed toward a process for preparing oxazoline (II) in a single step.

    摘要翻译: PCT No.PCT / US91 / 07608 Sec。 371日期:1993年4月22日 (IV)的制备方法:包含a)使式(I)的恶唑啉化合物与式(Ⅳ)的化合物接触:(ⅰ) (I)其中Z如上所定义,与试剂能够引起恶唑啉化合物(I)和本文所述的式(II)的恶唑啉化合物之间的平衡,并且试剂将平衡转化为恶唑啉化合物(II) 通过恶唑啉化合物(II)的优先沉淀; b)使化合物(II)与氟化剂接触,得到本文所述的式(III)的氟化恶唑啉化合物; 和c)将式(III)化合物水解成式(IV)。 在替代实施方案中,该方法涉及在单步骤中制备恶唑啉(II)的方法。