Total Synthesis of Spirotryprostatin A, Leading to the Discovery of Some Biologically Promising Analogues
作者:Scott Edmondson、Samuel J. Danishefsky、Laura Sepp-Lorenzino、Neal Rosen
DOI:10.1021/ja983788i
日期:1999.3.1
The total synthesis of the title compound has been accomplished. A key step involves the oxidative rearrangement of the β-carboline derivative to an oxindole via the action of N-bromosuccinimide. From this point, a diketopiperazine was introduced. A thiophenyl group served as a precursor of the isopropylidene function. Implementation of the same sort of chemistry starting with a methoxytryptophan derivative
标题化合物的全合成已经完成。一个关键步骤涉及通过 N-溴代琥珀酰亚胺的作用将 β-咔啉衍生物氧化重排为羟吲哚。从这一点开始,引入了二酮哌嗪。噻吩基用作异亚丙基官能团的前体。从甲氧基色氨酸衍生物开始实施相同类型的化学反应导致母体结构。此外,已经表明,螺环前列腺素 A 的难以接近的异亚丙基侧链对于生物活性不是必需的。此外,三种缺乏二酮哌嗪系统的类似物被证明作为细胞周期抑制剂非常活跃。
Mg(ClO4)2-catalyzed intramolecular allylic amination: application to the total synthesis of demethoxyfumitremorgin C
作者:Danfeng Jiang、Zhengren Xu、Yanxing Jia
DOI:10.1016/j.tet.2012.03.097
日期:2012.6
A Mg(ClO4)2-catalyzed intramolecularamination of allylic alcohols with carbamate or sulfonamide nucleophiles to form substituted piperidine and pyrrolidine derivatives has been developed. This method has been successfully applied to the total synthesis of demethoxyfumitremorgin C.
Exploiting Sm(ii) and Sm(iii) in SmI2-initiated reaction cascades: application in a tag removal–cyclisation approach to spirooxindole scaffolds
作者:Susannah C. Coote、Seidjolo Quenum、David J. Procter
DOI:10.1039/c1ob05710c
日期:——
A tag removalâcyclisation sequence is described that is initiated by reduction using a Sm(II) species and completed by a Sm(III) Lewis acid that is formed in an earlier stage. Therefore, the reaction cascade utilises both oxidation states of a samarium reagent in discrete steps and allows access to privileged, pyrrolidinyl-spirooxindole scaffolds and analogues inspired by the anti-cancer natural product spirotryprostatin A.
The firsttotalsynthesis of the tremorgic mycotoxin furnitremorgin C (1a) employing 6-methoxy-N-hydroxytryptophan (5a) is presented. Our approach features formation of the nitrone (6a), stereoselective cycloaddition to yield 7a, ring opening and coupling with an L-proline derivative to form 14. Base-catalysed epimerisation gave 16, which was converted into the title compound by deprotection of the
The 3-methyl-6-methoxyindole 3 was converted into tryprostatin A (1) via a regiospecific bromination process coupled with the Schöllkopf chiral auxillary 7 to provide the 2-bromo-6-methoxy-tryptophan 8a as a key intermediate.