Home About us Contact
|
Home About us Contact | ||
|
|
||
Concise Total Synthesis (concise + total_synthesis)
Selected AbstractsConcise Total Syntheses of Variolin B (Ia) and Deoxyvariolin B (Ib).CHEMINFORM, Issue 52 2005Regan J. Anderson Abstract For Abstract see ChemInform Abstract in Full Text. [source] A Concise Total Synthesis of (+)-HeliotridineEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 22 2003Federica Pisaneschi Abstract A practical synthesis of the necine base (+)-heliotridine (1) is reported here. The present total synthesis is based on the highly selective 1,3-dipolar cycloaddition of (S)-3- tert -butoxypyrroline N -oxide (2) to the commercially available ethyl 4-bromocrotonate, followed by a suitable elaboration of the adduct. The synthesis gives a 17% overall yield from nitrone 2. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source] A Concise Total Synthesis of (+)-Neopeltolide,ANGEWANDTE CHEMIE, Issue 17 2010Haruhiko Fuwa Prof. Kurz und knapp: Eine Totalsynthese des stark antiproliferativen marinen Makrolids (+)-Neopeltolid setzt auf Olefinmetathesen als strategische Elemente. Durch diese kürzeste bekannte Synthese wird (+)-Neopeltolid in nur 13,Stufen ausgehend von käuflichen Verbindungen erhalten. [source] ChemInform Abstract: A Concise Total Synthesis of (+)-Tetrabenazine and (+)-,-Dihydrotetrabenazine.CHEMINFORM, Issue 32 2010Seung-Mann Paek Abstract Tetrabenazine (I) is applied in racemic form as drug for the treatment of chorea associated with Huntington,s disease. [source] Highly Efficient and Mild Cascade Reactions Triggered by Bis(triphenyl)oxodiphosphonium Trifluoromethanesulfonate and a Concise Total Synthesis of Camptothecin.CHEMINFORM, Issue 38 2007Hai-Bin Zhou Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Concise Total Synthesis of (.+-.)-Marcfortine B.CHEMINFORM, Issue 31 2007Barry M. Trost Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Concise Total Synthesis of (.+-.)-Maritidine.CHEMINFORM, Issue 38 2003Claire Bru No abstract is available for this article. [source] Asymmetric Epoxidation of Homoallylic Alcohols and Application in a Concise Total Synthesis of (-)-,-Bisabolol and (-)-8-epi-,-Bisabolol.CHEMINFORM, Issue 25 2003Naoya Makita Abstract For Abstract see ChemInform Abstract in Full Text. [source] Concise Total Synthesis of the Thiazolyl Peptide Antibiotic GE2270,ACHEMISTRY - A EUROPEAN JOURNAL, Issue 8 2008Oscar Delgado Dr. Abstract The potent antibiotic thiazolylpeptide GE2270,A was synthesized starting from N - tert -butyloxycarbonyl protected valine in a longest linear sequence of 20 steps and with an overall yield of 4.8,%. Key strategy was the assembly of the 2,3,6-trisubstituted pyridine core by consecutive cross-coupling reactions starting from 2,6-dibromo-3-iodopyridine. The complete Southern fragment was installed by Negishi cross-coupling of 3-zincated 2,6-dibromopyridine at the terminal 2-iodothiazole of a trithiazole (87,%). The substituent at C-6 representing the Northern part of the molecule was introduced in form of the truncated tert -butyl 2-bromothiazole-4-carboxylate after metalation to a zinc reagent by another Negishi cross-coupling (48,%). Decisive step of the whole sequence was the macrocyclization to a 29-membered macrolactam, which was conducted as an intramolecular Stille cross-coupling occurring at C-2 of the pyridine core and providing the desired product in 75,% yield. The required stannane was obtained by amide bond formation (87,%) between a complex dithiazole fragment representing the Eastern part of GE2270,A and a 3,6-disubstituted 2-bromopyridine. Final steps included attachment of a serine-proline amide dipeptide to the Northern part of the molecule (65,%), formation of the oxazoline ring and silyl ether deprotection (55,% overall). [source] Rhodium-Catalyzed Asymmetric Nitroallylation of Arylmetallics with Cyclic Nitroallyl Acetates and Applications in Organic SynthesisEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 18 2006Lin Dong Abstract Highly enantioselective rhodium-catalyzed nitroallylations of arylboronic acids and arylzinc chlorides with cyclic nitroallyl acetates are described. Catalyst screening indicated that the rhodium complex of [Rh(OH)(COD)]2 and optically pure binap is the optimal catalyst for the nitroallylation of arylboronic acids with 2-nitrocyclohex-2-enyl esters, providing good yields and high enantioselectivities of up to 99,% ee. The rhodium complex prepared from Rh(acac)(C2H4)2 and (R)-binap efficiently catalyzed the nitroallylation of arylzinc chlorides with 2-nitrocyclohex-2-enyl acetate at 0 °C in high yields of up to 93,% and with high enantioselectivities of up to 96,% ee. A number of synthetically useful intermediates with high optical purity were prepared with this reaction as starting point: concise total syntheses of optically pure (+)-,-lycorane in 53,% overall yield and of (+)-,-lycorane in 52,% overall yield were achieved by commencing with the asymmetric nitroallylation of 3,4-methylenedioxyphenylzinc chloride with 2-nitrocyclohex-2-enyl acetate. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Concise Synthesis of (±)-Aurantioclavine through a Base-Promoted Pictet,Spengler ReactionEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 33 2009Koji Yamada Abstract A concise total synthesis of (±)-aurantioclavine (1) was completed in three steps through the base-promoted Pictet,Spengler reaction of Nb -benzylserotonin with 3-methylbut-2-enal. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] | ||||||||||||||||||||||