Asymmetric synthesis of the benzoquinoid ansamycin antitumor antibiotics: total synthesis of (+)-macbecin
摘要:
A convergent asymmetric synthesis of the antitumor antibiotic macbecin I has been achieved. Six of the seven stereogenic centers within the target structure were controlled using asymmetric aldol methodology, while the final stereogenic center was established through internal asymmetric induction. Fragment coupling was accomplished using a mild, titanium tetrachloride mediated aldol reaction. The C1-C5 unsaturated dienic ester was stereoselectively incorporated through a kinetically controlled Horner-Emmons olefination. Macrolactamization and subsequent refunctionalization afforded macbecin I.
Asymmetric synthesis of the benzoquinoid ansamycin antitumor antibiotics: total synthesis of (+)-macbecin
摘要:
A convergent asymmetric synthesis of the antitumor antibiotic macbecin I has been achieved. Six of the seven stereogenic centers within the target structure were controlled using asymmetric aldol methodology, while the final stereogenic center was established through internal asymmetric induction. Fragment coupling was accomplished using a mild, titanium tetrachloride mediated aldol reaction. The C1-C5 unsaturated dienic ester was stereoselectively incorporated through a kinetically controlled Horner-Emmons olefination. Macrolactamization and subsequent refunctionalization afforded macbecin I.
Theoretical and Experimental Determination of the Effects Governing the Transannular Diels−Alder Reaction of Trans−Trans−Cis Systems with or without Activation of the Dienophile
作者:Samuel Fortin、Louis Barriault、Yves L. Dory、Pierre Deslongchamps
DOI:10.1021/ja0109491
日期:2001.8.1
A thorough study of the transannularDiels-Alder (TADA) reaction of trans-trans-cis macrocyclic trienes was carried out. It led to a better understanding of various parameters that govern the TADA reaction in particular and the Diels-Alder reaction in general. Thus, carbonyl activation of the dienophile and substitution of the diene are discussed, as well as the presence of substituents on the macrocycle
对反-反-顺大环三烯的跨环狄尔斯-阿尔德(TADA)反应进行了深入研究。它有助于更好地了解控制 TADA 反应的各种参数,以及一般的 Diels-Alder 反应。因此,讨论了亲二烯体的羰基活化和二烯的取代,以及大环上取代基的存在及其在过渡态水平上的各自影响。
Total Synthesis of (−)-Nodulisporic Acids D, C, and B: Evolution of a Unified Synthetic Strategy
作者:Yike Zou、Xiangqin Li、Yun Yang、Simon Berritt、Jason Melvin、Stephen Gonzales、Matthew Spafford、Amos B. Smith
DOI:10.1021/jacs.8b04053
日期:2018.8.1
A unified synthetic strategy leading to the total synthesis of (-)-nodulisporic acids D, C, and B is described. Key synthetic transformations include a nickel-chromium-mediated cyclization, an aromatic ring functionalization employing a novel copper-promoted alkylation, a palladium-catalyzed cross-coupling cascade/indole ring construction, and a palladium-mediated regio- and diastereoselective allylic
描述了导致 (-)-球孢酸 D、C 和 B 全合成的统一合成策略。关键的合成转化包括镍铬介导的环化、采用新型铜促进的烷基化的芳环官能化、钯催化的交叉偶联级联/吲哚环结构以及钯介导的区域和非对映选择性烯丙基取代/环化反应,后者构建环D。
Total Synthesis of (−)-Nodulisporic Acid D
作者:Yike Zou、Jason E. Melvin、Stephen S. Gonzales、Matthew J. Spafford、Amos B. Smith
DOI:10.1021/jacs.5b04728
日期:2015.6.10
A convergent total synthesis of the architecturally complex indole diterpenoid (-)-nodulisporic acidD has been achieved. Key synthetic transformations include vicinal difunctionalization of an advanced α,β-unsaturated aldehyde to form the E,F-trans-fused 5,6-ring system of the eastern hemisphere and a cascade cross-coupling/indolization protocol leading to the CDE multisubstituted indole core.
结构复杂的吲哚二萜 (-)-nodulisporic 酸 D 的收敛全合成已经实现。关键的合成转化包括先进的 α,β-不饱和醛的邻位双官能化以形成东半球的 E,F-反式融合 5,6-环系统和导致 CDE 多取代吲哚的级联交叉偶联/吲哚化方案核。
Total Syntheses of Furaquinocin A, B, and E
作者:Barry M. Trost、Oliver R. Thiel、Hon-Chung Tsui
DOI:10.1021/ja0364118
日期:2003.10.1
A modular approach to the total synthesis of furaquinocins culminated in the total syntheses of furaquinocin A, B, and E. A Pd-catalyzed dynamic kinetic asymmetric transformation (DYKAT) on carbonates derived from Baylis-Hillman adducts, followed by a reductive Heckcyclization allows the enantio- and diastereoselective construction of dihydrobenzofuran 32. Introduction of a double unsatured side chain