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Showing 1 to 20 of 58 for “"Stereoselective Synthesis"”.
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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
… metathesis). D4 C nucleoside analogues are synthesised in a three step procedure, and 1’-aryl ribofuranoses are constructed in a four step procedure. The target compounds were prepared in an excellent enantio and diastereopurity, in good overall yields. The yield in the synthesis of …
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Stereoselective synthesis of perhydrobenzo[4.5.6]cholestanes
… has been developed for the stereocontrolled synthesis of pentacyclic steroids! with the new six-membered ring attached to the C(4) and C(6) positions. Cholesterol was converted into 3β-hydroxycholest-4-en-6-one by standard methods, and the corresponding 3α-isomer was obtained through …
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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 in stereoselective synthesis via reissert compound chemistry
… at developing methodology for the asymmetric synthesis of some isoquinoline alkaloids through Reissert compound chemistry. The stereochemistry of lepidine and isoquinoline Reissert compounds has not been reported. To better understand the stereochemistry of these compounds, selected Reissert …
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Stereoselective synthesis : studies involving dipole-stabilized carbanions alpha to nitrogen
… are key reagents and intermediates in organic synthesis. An exciting and growing field is the use of organolithiums in enantioselective synthesis. The often complex nature of these compounds makes their implementation towards the synthesis of natural products or pharmaceutical targets a …
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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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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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Stereoselective synthesis of 1,2-disubstitued βeta-amino alcohols and amino thiols
This thesis covers the development and implementation of two distinct methodologies, both of which provide access to enantiomerically enriched, vicinally functionalized products. Chapter 1 provides background and a brief introduction of the activation of Group 16 Lewis acids by Lewis bases. Chapter …
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Studies toward a stereoselective synthesis of the lower half of tetronolide
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Chemistry, 1987.
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Stereoselective synthesis of all-C quaternary stereocentres using non-enolisable 1,3-dialdehydes
The efficient synthesis of all-C quaternary centres as part of an acyclic contiguous stereoarray is a highly challenging synthetic operation. Investigations have been carried out into using non-enolisable 1,3-dialdehydes, under MgBr2•OEt2 chelation control, as small building blocks for the …
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Design and development of photobiocatalytic methods for the stereoselective synthesis of alcohols
Recientemente, la fotoquímica y la biocatálisis han cobrado gran relevancia en el desarrollo de compuestos inaccesibles mediante métodos tradicionales. La integración de ambas disciplinas abre nuevas posibilidades para diseñar procesos químicos operando bajo condiciones suaves y en línea con los …
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The stereoselective synthesis of a novel aromatic peptide nucleic acid (APNA) oligomer
The synthesis of the thymine derivative (S)-50, was achieved in high enantiomeric purity (98% ee). The (R) enhanced enantiomer was also synthesized with moderate enantiomeric purity (46% ee). This acyclic pyrimidine analog ((S)-50) is a useful building block for the synthesis of a novel class of …
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Stereoselective synthesis and iterative coupling of Csp3 boronates for automating small molecule synthesis
… A broadly applicable automated process for the synthesis of different classes of small molecules has thus far remained elusive. To enable the more generalized automation of small molecule synthesis, a common building block-based strategy and a common purification process for the preparation of …
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Stereoselective synthesis 2-C-alkylglucosides, potential inhibitors of mycobacterial MshB and related enzymes
… drugs. It was shown that the stereoselectivity synthesis of C-2 alkyl glucoside gave a key intermediate for the suitable synthesis of glycosyl donors. In addition, we achieved the preparation of D-inositol derivative chirally pure and having the hydroxyl at the 1-position. However, the attempted …
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Catalytic osmylation of dienes : mechanistic studies and applications to the stereoselective synthesis of polyols
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 1991.
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The stereoselective synthesis of iodinated analogues of reboxetine: new imaging agents for the noradrenaline transporter
… of an iodinated analogue of reboxetine were stereoselectively synthesised and biologically evaluated in an effort to understand the relationship between stereochemistry and potency. All four compounds were found to have nanomolar affinity for the noradrenaline transporter. Of most interest …
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Development of an approach towards the stereoselective synthesis of the cyclobutyl isomer of presqualene pyrophosphate
Restriction data tranferred 2014-07-01T11:13:39-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission
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One-Pot catalysis and multicomponent cascade reactions for the stereoselective synthesis of Pyrrolidine and indole derivatives
En esta memoria se encuentran recogidos los resultados referidos al estudio de nuevos procesos multicatalíticos en cascada "one-pot" y procesos multicomponente para la síntesis de compuestos heterocíclicos. Esta memoria se ha dividido en dos capítulos. En el Capítulo 1, se describen nuevas síntesis …
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