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Showing 1 to 20 of 225 for “"stereoselective"”.
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Stereoselective synthesis of piperidines
… using TMSC1 to give cyclic iminium salts v. Diastereoselective reduction of the iminium salts v with NaBH(OAc)[sub]3 gave piperidines vi which, after cleavage of the chiral protecting group gave the desired enantiomerically-enriched, 2-substituted piperidines vii. [Illustrated] The piperidines …
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Stereoselective Synthesis of Trisubstituted Olefins
A new method for the highly stereoselective synthesis of trisubstituted olefins is presented. The method involves the stereoselective construction of various $\beta$-hydroxy phosphonamidates followed by their thermolysis to provide trisubstituted olefins in extremely high geometrical purity …
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Stereoselective synthesis of artificial C-nucleosides
Reported herein is a conceptually new synthetic route to 1’-aryl C-ribofuranosides and their 2’,3’-didehydro 2’,3’-dideoxy (D4) analogues. We have successfully implemented a divergent synthetic route capable to reach two important, biologically significant groups of compounds. The first two …
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Studies on Stereoselective Methods of Synthesis
Made available in DSpace on 2014-12-10T23:01:51Z (GMT). No. of bitstreams: 1 7414521.pdf: 3558344 bytes, checksum: 642fc4f2a0d4375d6199e9bdb4a47064 (MD5) Previous issue date: 1974
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Conformational Effects of Stereoselective Photochemical Isomerizations
Made available in DSpace on 2014-12-09T17:36:49Z (GMT). No. of bitstreams: 1 7021004.pdf: 4933093 bytes, checksum: e9eb0ca1133273d512299de904b7befe (MD5) Previous issue date: 1970
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Stereoselective synthesis of perhydrobenzo[4.5.6]cholestanes
… Preliminary investigations into the stereoselective reduction of the olefinic bond in the 4α.5α-isomer, resulted in the formation of a new class of. hexahydrobenzo[4.5.6]cholestane derivatives. The structural and conformational properties of the condensation products were studied with …
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Use of organocatalysts in stereoselective organic synthesis
The main topic of thesis is the use of organocatalysis to synthesize cyclobutanones derivatives. Cyclobutanone derivatives are useful molecular building blocks for the construction of complex molecular structures. Surprisingly, however, the use of organocatalysts to functionalize cyclobutanones is …
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Stereoselective reactions of 16-Methylene 19-Norsteroids
The influence of the 17-substituent upon epoxidation of 3-methoxy-16-methylene-estra- 1,3,5(10)-trien-17-one and the derived 17β-hydroxy and 17β-acetoxy compounds was investigated. Alkaline hydrogen peroxide epoxidation of 3-methoxy-16-methyleneestra- 1,3,5(10)-trien-17-one occurred in good yields, …
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New Methods for the Stereoselective Synthesis of Olefins
Made available in DSpace on 2014-12-10T23:01:44Z (GMT). No. of bitstreams: 1 7412082.pdf: 4063012 bytes, checksum: 607c326a410c5a3da487b28ad2f73993 (MD5) Previous issue date: 1973
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Studies toward the stereoselective total synthesis of tedanolide
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 1997.
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Studies in stereoselective synthesis via reissert compound chemistry
Isoquinoline alkaloids have long been known for their biological activity. Many of the isoquinoline alkaloids have been made as racemic mixtures. The present investigation was aimed at developing methodology for the asymmetric synthesis of some isoquinoline alkaloids through Reissert compound …
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Studies directed towards the stereoselective total synthesis of miyakolide
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 1999.
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LIGHT AND ELECTRICITY: POWERFUL TOOLS FOR NEW SUSTAINABLE STEREOSELECTIVE SYNTHESIS
… of β-Naphtylamines derivatives; the stereoselective cyclization of aryl-enones under homogeneous and heterogeneous conditions and the late-stage C-H iron (III) catalyzed electrophotochemical perfluoroalkylation. Chapter 1 provides a detailed description of the synthetic techniques …
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The Development of New Stereoselective Transformations Using Alkenyl Boronate Complexes
… have emerged as powerful reagents for the stereoselective synthesis of chiral boronic esters via multicomponent coupling. These complexes can react with electrophiles through a 1,2-metalate rearrangement process, resulting in the net addition of a carbon-based migrating group and the …
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Brønsted acid-catalyzed stereoselective allylation of exo-glycals with allyltrimethylsilane
… procedures, this reaction proceeds in a diastereoselective manner to afford α-allyl substituted pyranose.
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Stereoselective synthesis : studies involving dipole-stabilized carbanions alpha to nitrogen
… organolithiums to form carbon-carbon bonds in a stereoselective and predictable way is vital to their success in organic synthesis. The first chapter in this thesis summarizes the current mechanistic understanding of asymmetric carbon-carbon bond formation adjacent to nitrogen. A brief literature …
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Applications of 2,3-Diketoesters in Organic Synthesis and Stereoselective Transformations
Dimethyldioxyrane oxidation of δ-hydroxy-α-diazo-β-ketoesters that are prepared by zinc triflate catalyzed Mukaiyama-aldol condensation of methyl diazoacetoacetates with aldehydes, occurred in quantitative yield to form dihydrofuranols that undergo acid catalyzed dehydration under mild conditions …
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Stereoselective and Economical Methods for Chemical Synthesis of Essential Medicines
… bedaquiline, and diazepam was investigated. Stereoselective strategies and cost-of-goods reduction more broadly are described. Lastly, a perspective on reproductive health safety in the chemical laboratory is presented. Chapter 1: Diazotization of S-Sulfonyl-Cysteines. We report the synthesis …
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Studies in the stereoselective synthesis of 1,1-disubstituted 1,2,3,4-tetrahydroisoquinolines
… the alkaloid exhibit undesired side effects. The stereoselective synthesis of 1, 1-disubstituted 1,2,3,4- tetrahydroisoquinolines using Reissert compound chemistry containing chiral acyl auxiliaries was studied with the ultimate goal of synthesizing spirobenzylisoquinoline alkaloids.
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