Enantiopure Chiral (2,4,6-Triisopropylbenzoyl)oxy-[D<sub>1</sub>]methyllithium: Configurational Stability, Reactions, and Mechanistic Studies
作者:Dagmar C. Kapeller、Friedrich Hammerschmidt
DOI:10.1021/jo802625q
日期:2009.3.20
The configurationalstability of enantiopure chiral (2,4,6-triisopropylbenzoyl)oxy-[D1]methyllithium generated by a tin−lithium exchange was tested on the macroscopic time scale, employing trapping experiments with benzaldehyde. It was found to be configurationally stable for minutes at −78 °C and to be an appropriate substitute for the carbamoyloxy-substituted analogue in terms of cleavage. Its addition
在宏观时间尺度上测试了由锡-锂交换产生的对映纯手性(2,4,6-三异丙基苯甲酰基)氧基-[D 1 ] 甲基锂的构型稳定性,采用苯甲醛捕获实验。发现它在 -78 °C 下构型稳定数分钟,并且在裂解方面是氨基甲酰氧基取代类似物的合适替代品。研究了将其添加到几种亲电子试剂中,从而得出了制备手性伯氘化醇的方案,例如合成 2-苯基-[1-D 1]98% 对映体过量 (ee) 的乙醇。此外,通过标记底物的光谱研究解决了这种芳酰氧基甲基锂的对映异构化和分解机制。它通过形成乙烯(次要途径)和n- BuLi同系化最多三个亚甲基单元而分解,然后交换为 Bu 4 Sn的丁基。
Incorporation of deuterium-labelled analogs of isopentenyl diphosphate for the elucidation of the stereochemistry of rubber biosynthesis
作者:Andrew A. Scholte、John C. Vederas
DOI:10.1039/b515750a
日期:——
prepared to investigate the detailed stereochemicalcourse of addition of C5 units during rubber biosynthesis in Hevea brasiliensis and Parthenium argentatum. These analogs were incorporated into the cis-polyisoprene chain by rubber transferase in rubber particles, and the stereochemistry was determined by 2H-NMR analysis of the polymer or of levulinic acid derivatives obtained from its ozonolytic degradation
The Stereochemical Course of DmdC, an Enzyme Involved in the Degradation of Dimethylsulfoniopropionate
作者:Anuj K. Chhalodia、Jeroen S. Dickschat
DOI:10.1002/cbic.202300795
日期:2024.2.16
The stereochemical course of the dehydrogenase DmdC involved in the degradation of the marine sulfur compound dimethyl sulfoniopropionate (DMSP) along the demethylation pathway has been investigated using stereoselectively deuterated substrate surrogates. The results revealed an anti elimination with removal of the 2-pro-R and the 3-pro-S hydrogenatoms.
使用立体选择性氘化底物替代物研究了脱氢酶 DmdC 的立体化学过程,该酶参与海洋硫化合物磺基丙酸二甲酯 (DMSP) 沿去甲基化途径的降解。结果揭示了去除 2- pro - R和 3- pro - S氢原子的反消除。