Results 221 to 230 of about 23,776 (268)
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Diastereoselective epoxidation of dipeptide olefins
Tetrahedron Letters, 1993Abstract m-Chloroperbenzoic acid (MCPBA) epoxidation of dipeptide olefins proceeds in high syndiastereoselectivity (38:1–300:1). This is partially caused by conformational constants introduce by the side chain that orients the allylic NH in a favorable position for hydrogen bonding to MCPBA.
S. ROMEO, D. RICH
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Diastereoselective Total Synthesis of Raputindole A
Organic Letters, 2018The first diastereoselective total synthesis of the bisindole alkaloid raputindole A is reported. After Au(I)-catalyzed assembly of the cyclopenta[ f]indole tricycle, it was possible to hydrogenate the indene double bond regio- and diastereoselectively through iridium catalysis, guided by a preinstalled hydroxy function.
Mario Kock, Thomas Lindel
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Cyclohexylcarbonitriles: Diastereoselective Arylations with TMPZnCl·LiCl
The Journal of Organic Chemistry, 2012Deprotonating substituted cyclohexanecarbonitriles with TMPZnCl·LiCl affords zincated nitriles that diastereoselectively couple with aryl bromides in the presence of catalytic Pd(OAc)(2) and S-Phos. Steric and electronic effects influence the diastereoselectivity; 4-t-butyl-, 4-TBSO-, and 2-Me-cyclohexanecarbonitriles exert virtually complete ...
Robert J, Mycka +5 more
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Diastereoselective Preparation of Azetidines and Pyrrolidines
Organic Letters, 2010Iodine-mediated cyclization of homoallyl amines at room temperature delivered cis-2,4-azetidine through a 4-exo trig cyclization. Isomerization of iodo-azetidines to cis-pyrrolidines could be achieved by heating, with complete stereocontrol. The relative stereochemistry of the iodo-azetidines and pyrrolidines was confirmed by NMR spectroscopy and X-ray
Antonio, Feula +2 more
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Diastereoselective Alkylations of a Protected Cysteinesulfenate
The Journal of Organic Chemistry, 2009To further understand stereoselection in the alkylation of sulfenate anions, a protected cysteinesulfenate was generated in THF solution at low temperature. Introduction of a reactive alkylating agent brings about a cysteinyl sulfoxide in 51-75% yield, with diastereomeric ratios at the sulfinyl group ranging from 83:17 to 95:5.
Adrian L, Schwan +4 more
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Enantio- and diastereoselective Darzens condensations
Tetrahedron Letters, 2007AbstractChemInform 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.
Achard TJR +5 more
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Diastereoselective Synthesis of 2,3,4,5,6-Pentafluoroheptanes
The Journal of Organic Chemistry, 2009A stereocontrolled synthesis of alkanes containing five contiguous fluorine atoms is presented. The compounds were prepared by sequential fluorination of diastereoisomeric alcohol-diepoxides. The chemistry involved epoxide ring-opening with HF.NEt(3) and deshydroxyfluorination reactions of free alcohols with Deoxo-Fluor. The fluorination reactions were
Farran, Daniel +3 more
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A practical diastereoselective synthesis of (−)‐bestatin
Journal of Peptide Science, 2018Diastereoselective addition of nitromethane to Boc‐D‐Phe‐H in the presence of sodium hydride in diethyl ether/hexane containing 15‐crown‐5 and subsequent N,O‐protection with 2,2‐dimethoxypropane gave trans‐oxazolidine in a diastereomeric ratio of >16:1.
Suisheng Shang +2 more
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Diastereoselective Hydroboration of Isopropenylcyclopropanes
The Journal of Organic Chemistry, 1999Janine, Cossy +3 more
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Diastereoselective Cyclopentane Construction
The Journal of Organic Chemistry, 2000, Taber, , Wang, , Pahutski
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