Mild and Efficient α-Chlorination of Carbonyl Compounds Using Ammonium Chloride and Oxone (2KHSO<sub>5</sub>·KHSO<sub>4</sub>·K<sub>2</sub>SO<sub>4</sub>)
A simple protocol for the α-monochlorination of ketones and 1,3-dicarbonyl compounds utilizing NH4Cl as a source of chlorine and Oxone as an oxidant in methanol without catalyst is presented. The reaction proceeds at ambient temperature in yields ranging from moderate to excellent.
Method for the production of (r)-and (s)-8-chloro-6-hydroxy-octanic acid alkyl esters by enzymatic reduction
申请人:Muller Michael
公开号:US20050032180A1
公开(公告)日:2005-02-10
The invention relates to a method for the production of (R)- or (S)-8-chloro-6-hydroxyoctanoic acid alkyl esters of the general formula (R)-II or (S)-II
in which R has the meaning C
1-4
-alkyl, from 8-chloro-6-oxooctanoic acid alkyl esters of the general formula I
in which R has the above meaning, by enzymatic reduction using alcohol dehydrogenases, such as
Lactobacillus brevis
or
Thermoanaerobium brokii
, in the presence of cofactor regeneration systems.
The resulting (R)- and (S)-8-chloro-6-hydroxyoctanoic acid esters can be converted in a known manner into (R)-α-lipoic acid and (S)-α-lipoic acid, respectively.
本发明涉及一种生产通式为(R)-II或(S)-II的(R)-或(S)-8-氯-6-羟基辛酸烷基酯的方法。
其中 R 的含义为 C
1-4
-烷基,由通式 I 的 8-氯-6-氧代辛酸烷基酯组成
其中 R 具有上述含义,通过使用醇脱氢酶进行酶还原,如
乳酸杆菌
或
酵母菌
在辅因子再生系统存在的情况下进行酶还原。
得到的(R)-和(S)-8-氯-6-羟基辛酸酯可按已知方式分别转化为(R)-α-硫辛酸和(S)-α-硫辛酸。
Kirrmann,A.; Nouri-Bimorghi,R., Bulletin de la Societe Chimique de France, 1968, p. 3213 - 3220
作者:Kirrmann,A.、Nouri-Bimorghi,R.
DOI:——
日期:——
Metal-catalyzed organic photoreactions. One-step synthesis of chlorinated ketones from olefins by photooxidation in the presence of iron(III) chloride
作者:Akira Kohda、Keiko Ueda、Tadashi Sato
DOI:10.1021/jo00316a007
日期:1981.1
Ultrasound in oxochromium(VI)-mediated transformations. 2. Ultrasound-mediated preparation and applications of chromyl chloride