Asymmetric aldol approach to dibenzylbutyrolactone lignans: synthesis of (−)-(7′S)-hydroxymatairesinol and (−)-(7′S)-hydroxyarctigenin
摘要:
A competent and general asymmetric synthesis of 7'-hydroxydibenzylbutyrolactone lignans such as (7'S)-hydroxymatairesinol and (7'S)-hydroxyarctigenin has been reported from N-succinyl-2-oxazolidinone in six steps where diastereoselective aldol reaction and stereoselective alkylation serve as the key steps. (C) 2013 Elsevier Ltd. All rights reserved.
(+)- and (-)-Methylenolactocins and phaseolinic acids are synthesized in four steps via asymmetric syn- and anti-aldol reactions of chiral N- succinyl-2-oxazolidinones using the same set of reagents. (C) 2008 Elsevier Ltd. All rights reserved.
An expedient synthetic approach has been developed for the unified total synthesis of (+)-chinensiolide B and (+)-8-epigrosheimin. The point of divergence was provided by the lactone aldehyde 6, in which four contiguous stereocenters were achieved by stereocontrolled Evans syn-aldol reaction of R-carvone derived enantiopure aldehyde and chiral N-succinyl-oxazolidinone. The lactone aldehyde 6 was synthesized
已经开发了一种方便的合成方法,用于统一合成(+)-chinensiolide B和(+)-8-epigrosheimin。分歧点是由内酯醛6提供的,其中通过R-香芹酮衍生的对映纯醛和手性N-琥珀酰-恶唑烷酮的立体控制Evans syn-aldol反应获得了四个连续的立体中心。分三步以数克的量合成内酯醛6。高度优化的化学和立体选择反应以及官能团的相互转化使我们能够从6位组装(+)-chinensiolide B amd(+)-8-epigrosheimin。
Synthesis of (1Z)-deacylcnicin
作者:Kogaku Kimura、Toyonobu Usuki
DOI:10.1016/j.tetlet.2022.154102
日期:2022.9
Cnicin is a germacranolide sesquiterpene lactone with a 10-membered ring, two internal olefins, two exo olefins, and an estersidechain. The natural product is a potent inhibitor of Trypanosoma brucei, which causes human African trypanosomiasis. This study examined the synthesis of cnicin via the Evans syn aldol reaction, the indium-promoted diastereoselective Barbier reaction, and ring-closing metathesis
Cnicin 是一种germacranolide 倍半萜内酯,具有一个10 元环、两个内烯烃、两个外烯烃和一个酯侧链。该天然产物是一种有效的布氏锥虫抑制剂,可导致人类非洲锥虫病。本研究通过 Evans syn aldol 反应、铟促进的非对映选择性 Barbier 反应和闭环复分解 (RCM) 检查了 cnicin 的合成。虽然 RCM 不提供天然 (1 E )-形式作为主要产物,但实现了 (1 Z )-脱酰基菌素的合成。