尽管现代光谱方法取得了巨大进步,但有机合成在阐明复杂天然产物的完整结构方面继续发挥着关键作用。这种方法的优点是,即使没有固定的结构分配,逻辑和光谱比较的组合也可以得出正确的结构。在此,我们报告了对 ushikulide A 的这一策略的执行,这是一种新分离的、以前立体化学上未定义的寡霉素-芦他霉素家族成员。为了最大限度地提高合成效率,我们设想对正交反应性官能团进行化学选择性操作,特别是烯烃和炔烃作为某些羰基和羟基官能团的替代物。这种方法具有最大限度地减少合成路线所需的步骤数和保护基团的双重效果。该策略最终实现了 ushikulide A 的高效合成和立体化学分配。
The substratespectrum of the inverting alkylsulfatase Pisa1 was investigated using a range of sec‐alkyl sulfate esters bearing aromatic, olefinic and acetylenic moieties. Perfect enantioselectivities were obtained for substrates bearing groups of different size adjacent to the sulfate ester moiety. Insufficient selectivities could be doubled by using dimethyl sulfoxide (DMSO) as co‐solvent. Hydrolytically
Exploiting Orthogonally Reactive Functionality: Synthesis and Stereochemical Assignment of (−)-Ushikulide A
作者:Barry M. Trost、Brendan M. O’Boyle
DOI:10.1021/ja807127s
日期:2008.12.3
In spite of the tremendous advances in modern spectroscopic methods, organic synthesis continues to play a pivotal role in elucidating the full structures of complex natural products. This method has the advantage that, even in the absence of a firm structural assignment, a combination of logic and spectroscopic comparison can arrive at the correct structure. Herein, we report execution of this strategy
尽管现代光谱方法取得了巨大进步,但有机合成在阐明复杂天然产物的完整结构方面继续发挥着关键作用。这种方法的优点是,即使没有固定的结构分配,逻辑和光谱比较的组合也可以得出正确的结构。在此,我们报告了对 ushikulide A 的这一策略的执行,这是一种新分离的、以前立体化学上未定义的寡霉素-芦他霉素家族成员。为了最大限度地提高合成效率,我们设想对正交反应性官能团进行化学选择性操作,特别是烯烃和炔烃作为某些羰基和羟基官能团的替代物。这种方法具有最大限度地减少合成路线所需的步骤数和保护基团的双重效果。该策略最终实现了 ushikulide A 的高效合成和立体化学分配。
Total Synthesis and Stereochemical Assignment of (−)-Ushikulide A
作者:Barry M. Trost、Brendan M. O’Boyle、Daniel Hund
DOI:10.1021/ja906056v
日期:2009.10.21
We report the determination of the full stereostructure of (-)-ushikulide A (1), a spiroketal containing macrolide by total synthesis. Ushikulide A (1) was isolated from a culture broth of Streptomyces sp. IUK-102 and exhibits potent immunosuppressant activity (IC(50) = 70 nM). To embark upon an ushikulide A synthesis, a tentative assignment was made based on analogy to cytovaricin (2), a related macrolide
我们报告了 (-)-ushikulide A (1) 的完整立体结构的测定,这是一种通过全合成含有大环内酯的螺旋缩酮。Ushikulide A (1) 是从 Streptomyces sp. 的培养液中分离出来的。IUK-102 并表现出有效的免疫抑制活性 (IC(50) = 70 nM)。为了着手进行 ushikulide A 合成,基于与 cytovaricin (2) 的类比进行了初步分配,这是一种从 Streptomyces diastatochromogenes 培养物中分离出来的相关大环内酯,其完整结构以前是通过合成和 X 射线晶体学确定的。这份报告描述了几个关键步骤的研究,即由双核锌 ProPhenol 络合物催化的直接醛醇反应,金属催化的 spiroketalization,以及应用前所未有的简单饱和醛与丙炔酸甲酯的不对称炔化反应来制备用于 Marshall-Tamaru 炔丙基化的亲核伙伴。这些研究最终实现了
One-Pot Deracemization of<i>sec</i>-Alcohols: Enantioconvergent Enzymatic Hydrolysis of Alkyl Sulfates Using Stereocomplementary Sulfatases
作者:Markus Schober、Michael Toesch、Tanja Knaus、Gernot A. Strohmeier、Bert van Loo、Michael Fuchs、Florian Hollfelder、Peter Macheroux、Kurt Faber
DOI:10.1002/anie.201209946
日期:2013.3.11
Hand in hand: The title transformation was achieved using a pair of sulfatases acting through inversion and retention of configuration on opposite substrate enantiomers. Using Pseudomonas aeruginosa arylsulfatase PAS with alkylsulfatase PISA1 in one‐pot leads to sec‐alcohols (80 to >99 % conversion) with 91 to greater than 99 % ee.