Asymmetric Synthesis of Gonytolide A: Strategic Use of an Aryl Halide Blocking Group for Oxidative Coupling
作者:Xiaowei Wu、Takayuki Iwata、Adam Scharf、Tian Qin、Kyle D. Reichl、John A. Porco
DOI:10.1021/jacs.8b02535
日期:2018.5.9
The first synthesis of the chromanone lactone dimer gonytolide A has been achieved employing vanadium(V)-mediated oxidative coupling of the monomer gonytolide C. An o-bromine blocking group strategy was employed to favor para- para coupling and to enable kinetic resolution of (±)-gonytolide C. Asymmetric conjugate reduction enabled practical kinetic resolution of a chiral, racemic precursor and the
色满酮内酯二聚体 gonytolide A 的首次合成是利用钒 (V) 介导的单体 gonytolide C 的氧化偶联实现的。采用邻溴封闭基团策略有利于对位偶联并实现 ( ±)-gonytolide C。不对称缀合物还原能够实现手性、外消旋前体的实际动力学拆分以及 (+)-gonytolide A 及其阻转异构体的不对称合成。
Triple-Dearomative Photocycloaddition: A Strategy to Construct Caged Molecular Frameworks
作者:Kaijie Ji、Jayachandran Parthiban、Steffen Jockusch、Jayaraman Sivaguru、John A. Porco
DOI:10.1021/jacs.4c02674
日期:2024.5.15
framework was serendipitously obtained in a single transformation via triple-dearomative photocycloaddition of chromone esters with furans. This caged structure was generated as part of an effort to access a tricyclic, oxygen-bridged intermediate enroute to the dihydroxanthone natural product nidulalin A. Reaction scope and limitations were thoroughly investigated, revealing the ability to access a multitude
通过色酮酯与呋喃的三重脱芳光环加成,在一次转化中偶然获得了前所未有的笼状2H-苯并二氧代五环十一烷骨架。这种笼状结构的产生是为了在二氢氧杂蒽酮天然产物 nidulalin A 的途中获得三环氧桥中间体。对反应范围和限制进行了彻底研究,揭示了在合成过程中获得多种具有合成挑战性的笼状支架的能力。两步序列。光物理研究为新型笼式支架的形成过程提供了关键的机制见解。
Vinylogous Addition of Siloxyfurans to Benzopyryliums: A Concise Approach to the Tetrahydroxanthone Natural Products
作者:Tian Qin、Richard P. Johnson、John A. Porco
DOI:10.1021/ja110698n
日期:2011.2.16
A concise approach to the tetrahydroxanthone natural products employing vinylogous addition of siloxyfurans to benzopyryliums and a late-stage Dieckmann cyclization has been developed. With this methodology, chiral, racemic forms of the natural products blennolides B and blennolide C have been synthesized in a maximum of four steps from a 5-hydroxychromone substrate. The regio- and diastereoselectivity of the vinylogous additions was probed using computational studies, which suggested the involvement of Diets Alder-like transition states.
TMSI-Promoted Vinylogous Michael Addition of Siloxyfuran to 2-Substituted Chromones: A General Approach for the Total Synthesis of Chromanone Lactone Natural Products
作者:Jie Liu、Zhanchao Li、Pei Tong、Zhixiang Xie、Yuan Zhang、Ying Li
DOI:10.1021/jo502571r
日期:2015.2.6
A concise and facile synthetic protocol for the construction of the 2-gamma-lactone chromanone skeleton has been achieved through a TMSI-promoted diastereoselective vinylogous Michael addition of siloxyfuran to 2-substituted chromones. The applicability of this method is demonstrated through the rapid access to the total syntheses of (+/-)-microdiplodiasone, (+/-)-lachnone C, and (+/-)-gonytolides C and G.