Synthesis of the (E)-dehydrobutyrine–thiazoline–proline–leucine fragment of vioprolides B and D
摘要:
A procedure is reported for the introduction of both the thiazoline and (E)-dehydrobutyrine components into a tetrapeptide-derived fragment of vioprolides B and D. The (E)-dehydrobutyrine is introduced first but, as the carbon-carbon double-bond of the dehydrobutyrine appeared incompatible with an adjacent thiol, the thiazoline was assembled by dehydration of a serine containing thioamide not by dehydration of a cysteinyl analogue. (C) 2013 Elsevier Ltd. All rights reserved.
尽管引入了商用圆二色性 (CD) 酶标仪,但光学手性化合物传感长期存在的不切实际限制了高通量实验技术的潜力和接受度。手性不对称反应传感通常需要结合 CD 分析进行紫外或荧光测量,以通过两条单独的校准曲线确定产率和对映体比率。在这里,我们介绍了一种策略,该策略通过专门使用 CD 分析和非手性探针来实现,该探针设计用于定量检测胺、氨基醇和所有标准手性氨基酸,从而消除了对紫外和荧光测量的需要。统一的 CD 传感优于传统的光学、NMR 和色谱方法,并提供速度、劳动力、减少化学废物产生的成本效益。它可以很容易地适应任何实验室,无需后处理即可应用于微尺度不对称反应筛选,并且普遍适用且不限于使用任何特定的光学探针。
A 2- or 4-nitrobenzenesulfonamide is allowed to react with an alkali metal alkoxide to remove a nitrobenzenesulfonyl group to thereby obtain an amine corresponding to the amide. Furthermore, a method for producing an amine derivative by allowing the resulting amine without isolation to react with an activated, substituted oxycarbonyl compound or an activated acyl compound is provided. According to this method, a corresponding free amine and its substituted derivative can be produced easily and industrially advantageously from the 2- or 4-nitrobenzenesulfonamide without using a thiol compound.
A 2- or 4-nitrobenzenesulfonamide is allowed to react with an alkali metal alkoxide to remove a nitrobenzenesulfonyl group to thereby obtain an amine corresponding to the amide. Furthermore, a method for producing an amine derivative by allowing the resulting amine without isolation to react with an activated, substituted oxycarbonyl compound or an activated acyl compound is provided. According to this method, a corresponding free amine and its substituted derivative can be produced easily and industrially advantageously from the 2- or 4-nitrobenzenesulfonamide without using a thiol compound.
Method for preparing optically active 3,4-dihydro-3,4-epoxy-2H-1-benzopyran compounds, intermediates therefor and uses thereof
申请人:YOSHITOMI PHARMACEUTICAL INDUSTRIES, LTD.
公开号:EP0456266A1
公开(公告)日:1991-11-13
The present invention provides an industrially valuable method for preparing an optically active 3,4-dihydro-3,4-epoxy-2H-1-benzopyran compound which is useful as a starting material for an optically active benzopyran compound with antihypertensive, coronary blood flow-increasing activities and the like, provides a diastereomeric ester compound which is useful as an intermediate for said epoxy compound and also provides a use of said diastereomeric ester compound in making of said epoxy compound, and further an optically active benzopyran compound which is useful as medicine.
An 8-methoxyquinolonecarboxylic acid derivative represented by general formula (I), and optical isomers, pharmaceutically acceptable salts and hydrates thereof, wherein R₁ represents hydrogen, lower alkyl, phenylalkyl or an in vivo hydrolyzable ester residue; R₂ represents hydrogen or methyl; and n represents an integer of 0 or 1. This derivative has a wide antimicrobial spectrum based on the activity potentiated in vitro and in vivo against gram-positive bacteria while retaining the potent antibacterial activity of the conventional quinolonecarboxylate bactericides against gram-negative bacteria. Since it scarcely has problematic side effects and is reduced in toxicity, it is promising as a bactericide having more excellent clinical effects.