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1.
Total synthesis of potent proteasome inhibitor salinosporamide A (1) has been accomplished, which features strictly substrate-controlled operations starting with the only chiral center of (R)-pyroglutamic acid. The consecutive quaternary carbons within 1 have been efficiently constructed by manipulation of two intramolecular reactions: (1) carbonate-mediated internal acylation of imidate ester (4 --> 14) and (2) selenocyclization of aldehyde to exocyclic methylene group (5 --> 18). 相似文献
2.
A simple stereocontrolled synthesis of salinosporamide A 总被引:1,自引:0,他引:1
A simple and effective stereocontrolled synthesis of salinosporamide A has been developed. This process, the first synthesis of salinosporamide A, is capable of providing the compound in substantial quantities for further biological studies. Salinosporamide A was of special interest as a synthetic target because of its potent in vitro cytotoxic activity against many tumor cell lines (IC(50) values of 10 nM or less). 相似文献
3.
A concise and straightforward 14-step total synthesis of (+/-)-salinosporamide A, based on a diastereoselective acid-catalysed intramolecular cyclisation of to the pyrrolidinone , and a regioselective reduction of the malonate derivative 8b to the aldehyde 9, is described. 相似文献
4.
Justin R. Struble 《Tetrahedron》2009,65(26):4957-3031
An N-heterocyclic carbene (NHC) catalyzed intramolecular lactonization to prepare densely functionalized bicyclic γ-lactam-γ-lactone adducts from enals is reported. This method has been applied to the formal synthesis of salinosporamide A, a potent 20S proteasome inhibitor and anti-cancer therapeutic. 相似文献
5.
Stereoselective functionalization of pyrrolidinone moiety towards the synthesis of salinosporamide A
Julien Barbion Geoffroy Sorin Mohamed Selkti Esther Kellenberger Rachid Baati Stefano Santoro Fahmi Himo Ange Pancrazi Marie-Isabelle Lannou Janick Ardisson 《Tetrahedron》2012,68(32):6504-6512
An important feature of the synthesis of salinosporamide A, a potent proteasome inhibitor, is the establishment of the quaternary stereocenter at C3. A new route has been developed based on the methylation of a functionalized pyrrolidinone. Direct methylation reaction led to the unwanted diastereomer; however, by means of a Corey–Chaykovsky reaction followed by LiAlH4 epoxide opening, the desired alcohol was obtained. The pyrrolidinone was elaborated through a key allylation reaction between a tertiary allyltitanium reagent and an aldehyde bearing a spiroketal moiety in α-position. 相似文献
6.
Virginie Caubert 《Tetrahedron letters》2007,48(3):381-384
(2R,3S)-α-Methylenelactam 3, the key intermediate in Corey’s syntheses of salinosporamide A, has been synthesized from (S)-methyl 2-hydroxymethylpyroglutamate through chemoselective O-protection, regio- and stereoselective N-methylnitrone cycloaddition and quaternarization-elimination reactions as the main steps. 相似文献
7.
Virginie Caubert 《Tetrahedron letters》2006,47(26):4473-4475
An α-methylenepyrrolidinone bearing all the functionalities and relative configurations of an advanced intermediate in the synthesis of salinosporamide A and analogues has been synthesized from methyl pyroglutamate through regio- and stereoselective N-methylnitrone cycloaddition. 相似文献
8.
[reaction: see text] A total synthesis of the salinosporamide analogue 3 is described that starts with the novel cyclization 4 --> 5. 相似文献
9.
Isabel Villanueva Margalef 《Tetrahedron》2008,64(34):7896-7901
Application of a sequential nickel-catalyzed reductive aldol cyclization-lactonization reaction in a short formal synthesis of salinsporamide A, a potent 20S proteasome inhibitor and anti-cancer compound, is described. 相似文献
10.
A convergent total synthesis of cytotoxic marine macrolide callipeltoside A is described. The synthesis highlights two stereoselective [4 + 2] annulations for the preparation of associated pyran rings. 相似文献
11.
Merrilactone A (1) has been shown to possess neurotrophic activity and thus is expected to hold therapeutic potential in the treatment of neurodegeneration diseases. In this paper, we report the total synthesis of (+/-)-1, employing, as key steps, a novel desymmetrization protocol of meso-diketone to construct the core cis-bicyclo[3.3.0]octyl system of 1 (3 --> 2) and a radical cyclization to install the highly congested C9-quaternary carbon (16 --> 17). 相似文献
12.
Hu Yuan Kaijian Bi Wanlin Chang Rongcai Yue Bo Li Ji Ye Qingyan Sun Huizi Jin Lei Shan Weidong Zhang 《Tetrahedron》2014
A total synthesis of Daphnodorin A, a member of the Daphnodorins, was accomplished. Key features of the synthetic strategy include construction of 2-substituted-3-functionalized benzofuran via intramolecular Heck reaction and a mild Barton–McCombie deoxygenation process mediated by triethylborane. The total synthesis provided Daphnodorin A in 19.7% or 5.6% overall yield over 7 or 15 steps. 相似文献
13.
14.
Miyagawa T Nagai K Yamada A Sugihara Y Fukuda T Fukuda T Uchida R Tomoda H Omura S Nagamitsu T 《Organic letters》2011,13(5):1158-1161
The first total synthesis of citridone A has been achieved through regioselective intramolecular iodocyclization and regio- and stereoselective Pd(0)-catalyzed coupling as key reactions. 相似文献
15.
The total synthesis of polygalolide A was accomplished through intramolecular C-glycosylation of glucal modified with siloxyfuran. The siloxyfuran group and siloxy substituent at the C-3 position played crucial roles in allowing direct access to the highly substituted oxabicyclo[3.2.1] core skeleton with correct quaternary stereogenic centers. 相似文献
16.
We have succeeded in the total synthesis of siomycin A, a representative compound of the thiostrepton family of peptide antibiotics, featuring the one-pot cyclization-elongation of our strategic intermediates and the late-stage formations of the thiazoline and dehydroamino acid moieties. 相似文献
17.
Diaportheone A (1), a chromone natural product was previously isolated from the endophytic fungi Diaporthe sp. P 133. Its structure was established by spectroscopic methods, however, its absolute configuration remained undefined. This study dealt on the total synthesis of diaportheone A (1) utilizing the cyclization and in situ thermal syn-elimination of a β-ketosulfoxide. The C-1R absolute configuration of the natural product was established by X-ray crystallography of the synthetic diaportheone A (1) (>99%?ee) and comparison with the optical rotation. 相似文献
18.
Stereoselective total synthesis of natural product crisamicin A (1) was accomplished for the first time via the Pd/TMTU-catalyzed alkoxycarbonylative annulation to generate a unique cis-pyran-fused lactone, an intermolecular Diels-Alder reaction to construct the pyranonaphthoquinone unit, and a novel Pd-thiourea pincer complex-catalyzed homocoupling of functionalized naphthoquinones. 相似文献
19.
The first total synthesis of mycestericin A (1) starting from tartrates is described. The Overman rearrangement of an allylic trichloroacetimidate generated a tetra-substituted carbon with nitrogen, and subsequent stereoselective transformations afforded the highly functionalized vinyl iodide. The cross-coupling of the vinyl iodide with a chiral organozinc species under Negishi conditions, followed by deprotection, completed the total synthesis of 1. 相似文献
20.
The antifungal natural product citrafungin A was synthesized using, as key steps, an asymmetric aldol reaction of a chiral oxazolidinone, diastereoselective alkylation of a chiral 1,3-dioxolan-2-one, semihydrogenation of an enyne, and selective methyl ester deprotection. 相似文献