Total Synthesis of Enigmazole A from <i>Cinachyrella enigmatica</i>. Bidirectional Bond Constructions with an Ambident 2,4-Disubstituted Oxazole Synthon
作者:Colin K. Skepper、Tim Quach、Tadeusz F. Molinski
DOI:10.1021/ja1016975
日期:2010.8.4
The first total synthesis of the cytotoxic marine macrolide enigmazole A has been completed in 22 steps (longest linear sequence). The sensitive, densely functionalized 2,4-disubstituted oxazole fragment was constructed using an efficient Negishi-type coupling of an oxazol-2-ylzinc reagent formed directly from the parent ethyl 2-iodooxazole-4-carboxylate by zinc insertion. Other key steps include a hetero-Diels-Alder cycloaddition to form the central embedded pyran ring, a Wittig reaction to unite Eastern and Western hemispheres, and a ring size-selective Keck macrolactonization.
Total Synthesis of (−)-Enigmazole A
作者:Yanran Ai、Mariya V. Kozytska、Yike Zou、Anton S. Khartulyari、Amos B. Smith
DOI:10.1021/jacs.5b11540
日期:2015.12.16
A highly convergent, stereocontrolledtotalsynthesis of the architecturally complex marine sponge metabolite (−)-enigmazole A has been achieved. Highlights include an unprecedented late-stage large-fragment Petasis–Ferrier union/rearrangement, a multicomponent Type I Anion Relay Chemistry (ARC) tactic, and a dithiane–epoxide union in conjunction with an oxazole-directed stereoselective reduction.
已经实现了结构复杂的海洋海绵代谢物 (-)-enigmazole A 的高度收敛、立体控制的全合成。亮点包括前所未有的后期大片段 Petasis-Ferrier 结合/重排、多组分 I 型阴离子中继化学 (ARC) 策略,以及二噻烷-环氧化物结合与恶唑定向的立体选择性还原。
Concise Total Synthesis of Enigmazole A
作者:Andreas Ahlers、Teresa de Haro、Barbara Gabor、Alois Fürstner
DOI:10.1002/anie.201510026
日期:2016.1.22
An efficient entry into the phosphorylated marine macrolide enigmazole A is described. Enigmazole A interferes with c‐Kit signaling by an as yet unknown mode of action and is therefore a potential lead in the quest for novel anticancer agents. Key to success is a gold‐catalyzed cascade comprising a [3,3]‐sigmatropic rearrangement of a propargyl acetate along the periphery of a macrocyclic scaffold