General synthetic routes to β-hydroxy-acids from t-butyl esters and the Reformatskii reaction
作者:D. A. Cornforth、A. E. Opara、G. Read
DOI:10.1039/j39690002799
日期:——
modified Reformatskii procedure which leads directly to the hydroxy-acid. With highly hindered ketones or under conditions of inverse addition, self-condensation of the Reformatskii reagents from the t-butyl esters of α-bromopropionic acid and α-bromoisobutyric acid seriously reduce the yields of β-hydroxy-esters.
An Efficient Directed Claisen Reaction Allows for Rapid Construction of 5,6-Disubstituted 1,3-Dioxin-4-ones
作者:Andrew Myers、Ziyang Zhang、Yoshiaki Kitamura
DOI:10.1055/s-0034-1378822
日期:——
chromatography and is amenable to large-scale synthesis. An efficient directed Claisen reaction between tert-butyl propionate and phenyl propionate is described. This enables a practical synthesis of 6-ethyl-2,2,5-trimethyl-4H-1,3-dioxin-4-one and thereby (Z)-[(4-ethylidene-2,2,5-trimethyl-4H-1,3-dioxin-6-yl)oxy]trimethylsilane, a key buildingblock in our synthesis of macrolide antibiotics. The three-step
摘要 描述了丙酸叔丁酯和丙酸苯酯之间的有效的定向克莱森反应。这使得能够实际合成6-乙基-2,2,5-三甲基-4H -1,3-二恶英-4-酮,从而合成(Z)-[(4-亚乙基-2,2,5-三甲基-4 H -1,3-二恶英-6-基)氧基]三甲基硅烷,是我们合成大环内酯类抗生素的重要组成部分。用于制备后一种物质的精心设计的三步路线无需色谱,可进行大规模合成。 描述了丙酸叔丁酯和丙酸苯酯之间的有效的定向克莱森反应。这使得能够实际合成6-乙基-2,2,5-三甲基-4H -1,3-二恶英-4-酮,从而合成(Z)-[(4-亚乙基-2,2,5-三甲基-4 H -1,3-二恶英-6-基)氧基]三甲基硅烷,是我们合成大环内酯类抗生素的重要组成部分。用于制备后一种物质的精心设计的三步路线无需色谱,可进行大规模合成。
Large-scale preparation of key building blocks for the manufacture of fully synthetic macrolide antibiotics
作者:Philip C Hogan、Chi-Li Chen、Kristen M Mulvihill、Jonathan F Lawrence、Eric Moorhead、Jens Rickmeier、Andrew G Myers
DOI:10.1038/ja.2017.116
日期:2018.2
Key building blocks for the production of fully synthetic macrolides have been scaled-up in first time pilot plant and kilo-lab campaigns. These building blocks have supported the discovery of new macrolide antibiotics as well as ongoing preclinical studies.
全合成大环内酯的生产关键组分首次在 pilot plant 和小规模试验中进行了扩大生产。这些关键组分不仅支持了新型大环内酯抗生素的发现,也为正在进行的前临床研究提供了支持。
Zn(ClO<sub>4</sub>)<sub>2</sub>·6H<sub>2</sub>O as a Powerful Catalyst for the Conversion of β-Ketoesters into β-Enamino Esters
Zn(ClO 4 ) 2 .6H 2 O proved to be a very powerfulcatalyst for the condensation of primary and secondary amines with β-ketoesters to give N-substituted β-enaminoesters.
Axially Chiral Guanidine as Highly Active and Enantioselective Catalyst for Electrophilic Amination of Unsymmetrically Substituted 1,3-Dicarbonyl Compounds
作者:Masahiro Terada、Megumi Nakano、Hitoshi Ube
DOI:10.1021/ja066808m
日期:2006.12.1
guanidine is found to function as an effective platform for asymmetric induction at the alpha-carbon of unsymmetrically substituted 1,3-dicarbonyl compounds. Highly efficient and enantioselective electrophilicamination of various 1,3-dicarbonyl compounds with azodicarboxylate was successfully achieved using the present chiral guanidine catalyst, which provides efficient access to the construction of