Enantioselective Total Synthesis of (+)‐Garsubellin A
作者:Dongseok Jang、Minchul Choi、Jinglong Chen、Chulbom Lee
DOI:10.1002/anie.202109193
日期:2021.10.11
cyclic molecular architecture, garsubellin A has garnered substantial synthetic interest, but its absolute stereostructure has been undetermined. We report here the first enantioselectivetotalsynthesis of (+)-garsubellin A. Our synthesis relies on stereoselective fashioning of a cyclohexanone framework and double conjugate addition of 1,2-ethanedithiol that promotes aldol cyclization to build the bicyclic
Garsubellin A 是一种能够增强胆碱乙酰转移酶的类萜,人们认为胆碱乙酰转移酶水平的降低在阿尔茨海默病的症状中发挥着重要作用。由于潜在有用的生物活性以及新颖的桥连和稠合环状分子结构,加苏贝林 A 引起了人们的广泛合成兴趣,但其绝对立体结构尚未确定。我们在这里报告了 (+)-garsubellin A 的第一个对映选择性全合成。我们的合成依赖于环己酮框架的立体选择性形成和 1,2-乙二硫醇的双共轭加成,促进羟醛环化以构建双环 [3.3.1] 骨架。十二步无保护基合成路线使得天然 (-)-garsubellin A 及其非天然 (+)-对映体的合成能够用于生物学评价。
Ruthenium-Catalyzed [2 + 2] Cycloadditions between Bicyclic Alkenes and Alkynyl Halides
作者:Karine Villeneuve、Nicole Riddell、Robert W. Jordan、Gavin C. Tsui、William Tam
DOI:10.1021/ol048111g
日期:2004.11.1
Ru-catalyzed [2 + 2] cycloadditions between norbornadiene and alkynylhalides were found to occur in moderate to good yields (32-89%). The presence of the halide moiety greatly enhances the reactivity of the alkyne component in the cycloaddition and can be transformed into a variety of products that are difficult or impossible to obtain via direct cycloaddition. [reaction: see text]