共查询到20条相似文献,搜索用时 15 毫秒
1.
The first total synthesis of (−)-diospongin B has been achieved starting from benzaldehyde using chiral allylation, a base catalyzed conjugate addition of an α,β-unsaturated ester and an intramolecular oxy-Michael reaction as the key steps in 16% overall yield. 相似文献
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G. ShankaraiahR. Sateesh Chandra Kumar B. PoornimaK. Suresh Babu 《Tetrahedron letters》2011,52(38):4885-4887
A simple and efficient stereoselective synthesis of naturally occurring pyrrolidine alkaloid, radicamine B has been accomplished in 13 steps from the commercially available starting materials with an overall yield of 9.75%. The synthesis utilizes Sharpless asymmetric epoxidation and Horner-Wadsworth-Emmons (HWE) olefination as key steps. 相似文献
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Toshiharu Arai 《Tetrahedron letters》2004,45(30):5921-5924
A stereoselective total synthesis of (+)-cylindricine C has been achieved starting with (S)-N-Boc-2-pyrrolidinone. The key elements of this synthesis involve the sequence of reactions including BF3-mediated addition of the allyl Grignard reagent to the cyclic imine, spirocyclization via enamine formation, and intramolecular Michael addition to form the tricyclic core. 相似文献
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A nine-step (longest linear) batch total synthesis of the cyclic hexadepsipeptide (−)-enniatin B is described. The synthesis minimizes precipitation during reaction conditions for adaptability to flow synthesis. The route was used to prepare >100 mg of the natural product. 相似文献
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The enantioselective total synthesis of the nonacyclic polypyrrolidinoindoline (−)-idiospermuline is described. Stereocontrolled formation of the vicinal quaternary carbon centers is achieved in a single step by dialkylation of an unsymmetrical prostereogenic dienolate with a tartrate-derived chiral dielectrophile. A catalyst-controlled diastereoselective Heck cyclization is employed to form the diaryl-substituted quaternary center. 相似文献
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Silvano Cruz-GregorioCristhian Espinoza-Rojas Leticia QuinteroFernando Sartillo-Piscil 《Tetrahedron letters》2011,52(48):6370-6371
A new application of the sequential hydrolysis-oxidation-Wittig olefination (SHOWO) protocol to a d-glucose derivative, and an anomeric deoxygenation reaction of a xylo-d-furanose derivative is presented for the five-step formal synthesis of (−)-Jaspine B. 相似文献
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J.S. Yadav K.V. PurnimaB.V. Subba Reddy K. NagaiahA.K. Ghamdi 《Tetrahedron letters》2011,52(50):6709-6712
A stereoselective synthesis of fragment A of cryptophycin is achieved utilizing the versatile Prins cyclization. Subsequently, the total synthesis of cryptophycin-24 (arenastatin A) has been accomplished by coupling it with the depsipeptide subunit. 相似文献
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Masaya Ichikawa 《Tetrahedron letters》2005,46(13):2327-2329
An enantioselective synthesis of (−)-incarvilline is presented, employing a three-component coupling reaction and an intramolecular enone-olefin [2+2] photocycloaddition followed by a SmI2-induced cyclobutane ring-opening reaction. 相似文献
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Toshiharu Takeuchi 《Tetrahedron letters》2008,49(45):6462-6465
Stereoselective synthesis of (−)-centrolobine, an anti-Leishmania agent, was accomplished via an intramolecular Barbier-type reaction of iodo-ester with n- or t-butyllithium followed by Lewis acid-promoted Et3SiH reduction of the resulting hemiacetal. 相似文献
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Maria GonzálezZoila Gándara Berta CoveloGenerosa Gómez Yagamare Fall 《Tetrahedron letters》2011,52(45):5983-5986
A total synthesis of (−)-muricatacin has been achieved using a commercially available starting material and our furan approach to oxacyclic systems, the proven scope of which is thus broadened. 相似文献
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Palakuri RameshH.M. Meshram 《Tetrahedron letters》2011,52(19):2443-2445
The total synthesis of (−)-cleistenolide, a novel natural product recently isolated from the annonaceae species cleistochlamys kirkii oliver, is described. The synthesis proceeds starting from easily accessible d-manitol using a selective benzoylation, a selective acetonide deprotection, silylprotection and ring-closing metathesis reaction. 相似文献
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Hiromasa Yokoe 《Tetrahedron letters》2008,49(21):3504-3506
The first enantioselective total synthesis of xanthatin, a xanthanolide sesquiterpenoid exhibiting potent antibacterial activity against MRSA, has been accomplished from an optically pure bicyclic lactone, previously synthesized by our group. 相似文献
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A 13-step, highly stereoselective synthesis of (−)-nakadomarin A has been achieved using the combination of a bifunctional organocatalyst controlled Michael addition, a nitro-Mannich/lactamization cascade, an alkyne ring-closing metathesis/syn-reduction, and furan/iminium ion cyclization/reduction as key steps. 相似文献
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John P. Cooksey Philip J. Kocieński Beatrice Pelotier Jean-Marc Pons 《Tetrahedron》2010,66(33):6462-6467
A synthesis of the β-lactone esterase inhibitors (−)-ebelactones A and B is described. The synthesis features the use of a Hoppe homoaldol reaction and a Cu(I)-mediated 1,2-metallate rearrangement of a metallated enol carbamate as key fragment linkage reactions. 相似文献
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The first total synthesis of (±)-cyclooroidin, a member of the pyrrole-imidazole alkaloid family recently isolated from the sponge Agelas oroides in optically pure form, is described. The synthesis was achieved in nine linear steps, with an overall yield of 10%. Key step was a Wolff bromoketone synthesis performed on the intermediate longamide B. 相似文献
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Tushar Kanti Chakraborty Vakiti Ramkrishna Reddy Amit Kumar Chattopadhyay 《Tetrahedron letters》2006,47(42):7435-7438
The total synthesis of (−)-clavosolide A is achieved employing a radical-mediated route to build the substituted tetrahydropyran unit, a Yamaguchi reaction to construct the diolide aglycon and the Schmidt method for the final glycosidation step. 相似文献