A mild hydrolysis of esters mediated by lithium salts
摘要:
When treated with amine bases such as triethylamine and various lithium salts in wet solvents, esters are efficiently hydrolyzed to the corresponding acids in good yields. Esters incorporating an alpha- or beta-heteroatom with respect to the ester carbonyl group are hydrolyzed rapidly even at room temperature. To further demonstrate the usefulness of this method, one example is provided where hydrolysis of acetylated camphorsultam is mediated by LiBr. (c) 2007 Elsevier Ltd. All riehts reserved.
Di-μ-hydroxy-bis(N,N,N′,N′-tetramethylenediamine)-copper(II) chloride [Cu(OH)·TMEDA]2Cl2: an efficient, practical catalyst for benzylation and allylation of amides
An efficient protocol for the benzylation or allylation of amides using the corresponding benzyl or allyl chlorides as electrophiles under basic conditions with commercially available 5 mol % of [Cu(OH)TMEDA]2Cl2 as catalyst was developed. Under these conditions, unprotected amino acids were benzylated without any racemization.
METHOD FOR THE PRODUCTION OF OPTICALLY ACTIVE ALPHA ALKYL CARBONYL COMPOUNDS
申请人:Breit Bernhard
公开号:US20100305352A1
公开(公告)日:2010-12-02
A method for the production of optically active α-alkylcarbonyl compounds with retention of the stereo information of the starting compound. The starting compound used here is a carbonyl compound which has, in the α-position, a leaving group which is substituted by an alkyl group with inversion of the configuration. The substitution of the leaving group is effected with the use of an alkylmagnesium Grignard and a zinc (II) salt or a zinc organyl. The method permits the production of optically active α-alkylcarbonyl compounds at very mild temperatures (for example 0° C.) with the use of starting compounds which are easy to prepare and economical and nontoxic catalysts, it also being possible to achieve a very high yield.
Stereoselective synthesis of the C3–C12 subunit of laulimalide
作者:Sadagopan Raghavan、Pradip Kumar Samanta
DOI:10.1016/j.tetlet.2013.12.040
日期:2014.1
A stereoselectivesynthesis of the C3–C12 subunit of the tumor growth inhibitors laulimalide is disclosed. The key steps of the synthesis include asymmetric alkylation using Oppolzer’s protocol and an asymmetric hetero-Diels–Alder reaction using Jacobsen’s catalyst. Substrate controlled diastereoselective Luche reduction followed by Ferrier type reactions are other key steps.
science. Methods for the incorporation of lightly fluorinated groups such as CF2H have been less well developed. Here we report the use of difluorinated diazoacetone as a practical reagent for the directsynthesis of CF2H-substituted 2-amidofurans through addition to ynamides. These newly designed difluorinated amidofurans were elaborated to create new nitrogen-containing frameworks that would be challenging
含有二氟甲基的分子的重要性是由它们在制药和农业化学科学中的潜在应用驱动的。掺入轻度氟化基团(例如CF 2 H)的方法还没有得到很好的发展。在这里,我们报告了使用二氟化重氮丙酮作为一种实用试剂,通过添加到ynamides直接合成CF 2 H 取代的2-酰氨基呋喃。这些新设计的二氟酰氨基呋喃经过精心设计,以创造新的含氮框架,否则很难获得。
Processes for the Preparation of Tasimelteon and Intermediates Thereof
申请人:Apotex Inc.
公开号:US20170355688A1
公开(公告)日:2017-12-14
The present invention provides processes for the preparation of Tasimelteon (1), as well as processes for the preparation of intermediates of Formulas (2), (3) and (4) useful in the preparation of Tasimelteon (1).