- Total synthesis of (8S,11R,12R)- and (8R,11R,12R)-topsentolide B 2 diastereomers and assignment of the absolute configuration
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An improved total synthesis of (8S,11R,12R)- and (8R,11R,12R)-topsentolide B2 diastereomers has been completed in eight steps with overall yields of 10.2% and 10.4%, respectively. The key steps involve a regioselective asymmetric dihydroxylation, diastereoselective Roush allylation, and ring closing metathesis. The stereochemistry of natural topsentolide B2 has been determined to be (8S,11R,12R) by comparison of the specific rotation.
- Fernandes, Rodney A.,Kattanguru, Pullaiah
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Read Online
- A Simple, Mild and General Oxidation of Alcohols to Aldehydes or Ketones by SO2F2/K2CO3 Using DMSO as Solvent and Oxidant
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A practical, general and mild oxidation of primary and secondary alcohols to carbonyl compounds proceeds in yields of up to 99% using SO2F2 as electrophile in DMSO as both the oxidant and the solvent at ambient temperature. No moisture- and oxygen-free conditions are required. Stoichiometric amount of inexpensive K2CO3, which generates easy to separate by-products, is used as the base. Thus, 5-gram scale runs proceeded in nearly quantitative yields by a simple filtration as the work-up. The use of a polar solvent such as DMSO, which usually promotes competing Pummerer rearrangement, is also noteworthy. This protocol is compatible with a variety of common N-, O-, and S-functional groups on (hetero)arene, alkene and alkyne substrates (68 examples). The protocol was applied (99% yield) to a formal synthesis of the important cholesterol-lowering drug Rosuvastatin. (Figure presented.).
- Zha, Gao-Feng,Fang, Wan-Yin,Leng, Jing,Qin, Hua-Li
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supporting information
p. 2262 - 2267
(2019/04/17)
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- A Transition-Metal-Free One-Pot Cascade Process for Transformation of Primary Alcohols (RCH2OH) to Nitriles (RCN) Mediated by SO2F2
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A new transition-metal-free one-pot cascade process for the direct conversion of alcohols to nitriles was developed without introducing an “additional carbon atom”. This protocol allows transformations of readily available, inexpensive, and abundant alcohols to highly valuable nitriles.
- Jiang, Ying,Sun, Bing,Fang, Wan-Yin,Qin, Hua-Li
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supporting information
p. 3190 - 3194
(2019/05/21)
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- Synthesis of (4: E,6 Z,10 Z)-hexadeca-4,6,10-trien-1-ol and (4 E,6 E,10 Z)-hexadeca-4,6,10-trien-1-ol, the pheromone components of cocoa pod borer moth Conopomorpha cramerella
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A concise and efficient synthesis of the pheromone components of the cocoa pod borer moth, namely (4E,6Z,10Z)-hexadeca-4,6,10-trien-1-ol and (4E,6E,10Z)-hexadeca-4,6,10-trien-1-ol, starting from commercially available materials, was reported. The overall yield was 30.4% and 27.4%, respectively. The stereoselective formation of (E,Z)- or (E,E)-conjugated double bond relied on Sonogashira coupling with (E)-5-bromopent-4-en-1-ol prepared from (E)-5-bromopent-4-enal and the stereoselective hydrogenation of the enyne, while the 10Z-double bond was formed by Wittig reaction from 4-hydroxybutanal and n-hexyltriphenylphosphonium bromide.
- Huang, Fei,Zhang, Yushun,Yao, Yun,Yang, Wanqiu,Tao, Yunhai
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p. 35575 - 35580
(2017/07/28)
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- Synthesis of epoxyisoprostanes: Effects in reducing secretion of pro-inflammatory cytokines IL-6 and IL-12
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Anti-inflammatory: The efficient and general synthetic route to the elusive epoxyisoprostanoid phospholipids PECPC and PEIPC, along with the isoprostanoids EC and EI, relies on a number of stereo- and chemoselective steps, including a C-H insertion for the rapid construction of the cyclopentanone ring. The synthesized compounds display unprecedented biological activity in reducing the secretion of pro-inflammatory cytokines. Copyright
- Egger, Julian,Bretscher, Peter,Freigang, Stefan,Kopf, Manfred,Carreira, Erick M.
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supporting information
p. 5382 - 5385
(2013/06/26)
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- Model studies on the pattern of volatiles generated in mixtures of amino acids, lipid-oxidation-derived aldehydes, and glucose
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The development of flavor and browning in thermally treated foods results mainly from the Maillard reaction and lipid degradation but also from the interactions between both reaction pathways. To study these interactions, we analyzed the volatile compounds resulting from model reactions of lysine or glycine with aldehydes originating from lipid oxidation [hexanal, (E)-2-hexenal, or (2E,4E)-decadienal] in the presence and absence of glucose. The main reaction products identified in these model mixtures were carbonyl compounds, resulting essentially from amino-acid-catalyzed aldol condensation reactions. Several 2-alkylfurans were detected as well. Only a few azaheterocyclic compounds were identified, in particular 5-butyl-2-propylpyridine from (E)-2-hexenal model systems and 2-pentylpyridine from (2E,4E)-decadienal model reactions. Although few reaction products were found resulting from the condensation of an amino acid with a lipid-derived aldehyde, the amino acid plays an important role in catalyzing the degradation and further reaction of these carbonyl compounds. These results suggest that amino-acid-induced degradations and further reactions of lipid oxidation products may be of considerable importance in thermally processed foods.
- Adams, An,Kitryte, Vaida,Venskutonis, Rimantas,De Kimpe, Norbert
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experimental part
p. 1449 - 1456
(2011/10/05)
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- Derivatives of erythromycylamine
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Three new groups of 9-N-substituted derivatives of erythromycylamine with superior oral activity against Gram-positive pathogens, new processes for preparing derivatives of erythromycylamine and aliphatic aldehydes by controlling the pH of the reaction and by catalytic hydrogenation, and pharmaceutical compositions and methods using the new compounds are provided.
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- Ozonolysis of alkenes and study of the reactions of polyfunctional compounds. XXXIII. Synthesis of (Z)-7-oxo-10-hexadecen-1-ol and its noranalog
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A pathway has been developed for the synthesis of (Z)-7-oxo-10-hexadecen-1-ol, which is a cancer inhibitor, and its noranalog, (Z)-7-oxo-10-pentadecen-1-ol, based on the partial ozonolysis of (Z,Z)-1,5-cyclooctadiene leading to 1,1-dimethoxy-8-tosyloxy-4Z-octene.Subsequent simple transformations of the hydrocarbon skeleton give the desired compounds in five steps.
- Odinokov, V. N.,Botsman, L. P.,Nagaeva, N. A.,Tolstikov, G. A.
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