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1.
[reaction: see text] A stereocontrolled total synthesis of (-)-kainic acid is described. A fully functionalized trisubstituted pyrrolidine ring was constructed by ring-closing metathesis of an acrylate derivative followed by an intramolecular Michael addition of the resultant alpha,beta-unsaturated lactone with high diastereoselectivity. Two alternative protocols for the construction of the alpha,beta-unsaturated lactone were also developed. 相似文献
2.
[reaction: see text] A highly stereoselective synthesis of (-)-kainic acid has been achieved in 14 steps and >7% overall yield starting from inexpensive trans-4-hydroxy-L-proline. The key steps are diastereoselective enolate alkylation and cuprate substitution reactions. 相似文献
3.
Hermet JP Viterisi A Wright JM McGrath MJ O'Brien P Whitwood AC Gilday J 《Organic & biomolecular chemistry》2007,5(22):3614-3622
A convenient method for the stereoselective synthesis of cyclic beta-amino esters from an iodo alphabeta-unsaturated ester and alpha-methylbenzylamine is described. Subsequent enolate generation and alkylation proceeds with complete stereocontrol, with the two stereogenic centres working together. In this way, a functionalised piperidine suitable for alkaloid natural product synthesis was prepared. The usefulness of the methodology is exemplified with the concise synthesis of a (-)-sparteine surrogate. 相似文献
4.
Orellana A Pandey SK Carret S Greene AE Poisson JF 《The Journal of organic chemistry》2012,77(12):5286-5296
An efficient synthesis of (-)-kainic acid, through a high-pressure-promoted Diels-Alder cycloaddition of a vinylogous malonate derived from 4-hydroxyproline, is described. The bicyclic adduct could be converted into the natural product with complete stereocontrol. 相似文献
5.
(+)-Benzoylselenopederic acid (1), a left half of (+)-pederin (3), was synthesized stereoselectively based on the Zn(BH4)2 reduction and total synthesis of (+)-pederin (3) was accomplished from 1 and the previously synthesized 2. 相似文献
6.
[reaction: see text] A concise and enantioselective synthesis of (-)-(alpha)-kainic acid in 13 steps with an overall yield of 15% is reported. The pyrrolidine kainoid precursor with the required C2/C3 trans stereochemistry was prepared with excellent diastereoselectivity (>20:1) via a MgI(2)-mediated ring expansion of a tertiary methylenecyclopropyl amide. A selective hydroboration was then employed to set the remaining stereochemistry at the C4 position en route to (-)-(alpha)-kainic acid. 相似文献
7.
A highly practical stereoselective total synthesis of (-)-kainic acid is described. This synthesis features the stereoselective alkylation of an iodolactone intermediate that was efficiently prepared from (+)-carvone and introduction of carboxylic acid by hydrolysis of a nitrile accompanied by epimerizaion. This synthetic route enabled us to obtain 14.6 g of (-)-kainic acid. 相似文献
8.
Two concise, high-yielding syntheses of enantioenriched (-)-kainic acid are presented. Both routes feature a Pd-catalyzed Zn-ene cyclization that proceeds with complete diastereoselectivity. The key step can be carried out on a multigram scale, and the overall yields are among the highest to date for this marine alkaloid. 相似文献
9.
Higashi T Isobe Y Ouchi H Suzuki H Okazaki Y Asakawa T Furuta T Wakimoto T Kan T 《Organic letters》2011,13(5):1089-1091
The efficient total syntheses of (+)-methoxyphenylkainic acid (3) and (+)-phenylkainic acid (4) were achieved using a rhodium carbenoid-mediated intermolecular C-H insertion reaction. Complete stereoselective construction of the kainoid skeleton was accomplished by utilizing the stereochemistry at the C-4 position as a pivotal stereogenic center. 相似文献
10.
Yamashita T Kawai N Tokuyama H Fukuyama T 《Journal of the American Chemical Society》2005,127(43):15038-15039
A stereocontrolled total synthesis of (-)-eudistomin C was accomplished in 18-step sequence with an overall yield of 7.7%. The synthesis features the diastereoselective Pictet-Spengler reaction of a tryptamine derivative and the Garner aldehyde catalyzed by Bronsted acids, and the unprecedented construction of the unusual oxathiazepine ring by intramolecular alkylation. 相似文献
11.
K Takahashi K Komine Y Yokoi J Ishihara S Hatakeyama 《The Journal of organic chemistry》2012,77(17):7364-7370
The total synthesis of (-)-englerin A, a potent and selective inhibitor of renal cancer cell lines, is described. The key feature includes the stereocontrolled construction of the cyclopentane structure by taking advantage of a base-promoted epoxynitrile cyclization. 相似文献
12.
[structure: see text] A highly stereocontrolled total synthesis of the cytotoxic macrolide (-)-callipeltoside A has been achieved in 23 steps (4.8% overall). Notable features include a novel asymmetric vinylogous aldol reaction to install the C13 stereocenter and (E)-trisubstituted alkene, an anti-selective aldol addition, a Sonogashira coupling, and, last, a Schmidt-type glycosylation to attach the sugar unit. 相似文献
13.
Mandal AK 《Organic letters》2002,4(12):2043-2045
[structure: see text] The highly stereocontrolled hydroboration of an alkene, a subsequent Suzuki-Miyaura cross-coupling reaction, a silylcupration on a nonterminal acetylene, and an iododesilylation were the key steps in a convergent total synthesis of (-)-ebelactone A. 相似文献
14.
A short, efficient, and stereoselective total synthesis of a pyrrolidine alkaloid: (-)-codonopsinine
An efficient total synthesis of antibiotic (-)-codonopsinine 1 with an overall yield of 44% was achieved from d-alanine as a chiral template. The key steps in our strategy are modified Sharpless asymmetric dihydroxylation reaction and the highly stereoselective intramolecular acid-catalyzed amidocyclization. 相似文献
15.
Hiroki Toya Takahito Satoh Kentaro Okano Kiyosei Takasu Masataka Ihara Atsushi Takahashi Haruo Tanaka Hidetoshi Tokuyama 《Tetrahedron》2014
Total synthesis of (−)- and (+)-petrosin was accomplished. Stereocontrolled construction of the quinolizidine ring was achieved through a diastereoselective Mannich reaction and an aza-Michael reaction. Head-to-tail dimerization was performed by assembly of the two monomers using Suzuki–Miyaura cross coupling and subsequent ring-closing metathesis to construct the 16-membered ring. Biological evaluation of synthetic (−)- and (+)-petrosin and its derivatives indicated that the bispiperidine structure was necessary for the inhibition of syncytium formation. 相似文献
16.
The vinyloxyborane(5), prepared from (+)--phenyl-3()-butanethioate, 9-BBN triflate and diisopropylethylamine, reacted with -(3-benzyloxypropylidene)benzylamine to give the β-benzylamino thiol ester(6) in a moderate yield, which was efficiently converted to the optically pure thienamycin intermediate(10). 相似文献
17.
The stereocontrolled total synthesis of (-)-ephedradine A has been accomplished. The synthesis features an asymmetric C-H insertion reaction, an intramolecular ester-amide exchange reaction, and a Sharpless asymmetric aminohydroxylation reaction. Construction of the complex macrocyclic ring was performed by Ns-strategy and an intramolecular aza-Wittig reaction. 相似文献
18.
19.
Sequential sigmatropic rearrangements (Claisen/Claisen and Claisen/Overman) of enantiopure allylic diols are described. The reactions proceeded in complete diastereoselectivity without protecting group manipulations. The sequential Claisen/Overman rearrangement was successfully applied to the total synthesis of (-)-kainic acid. 相似文献
20.
F.P. van Lier T.G.M. Hesp L.M. van der Linde A.J.A. van der Weerdt 《Tetrahedron letters》1985,26(17):2109-2110
(+)-Spathulenol was prepared for the first time in three reaction steps from (+)-aromadendrene by two subsequent ozonizations the second of which was regio- and stereoselective, followed by a Wittig reaction. The overall recycle yield was 13%. 相似文献