ChemInform Abstract: Intramolecular Michael Addition of N- and O-Centered Nucleophiles to Tethered Acrylates. The Role of Double-Bond Geometry in Controlling the Diastereoselectivity of Cyclizations Leading to 2,6-Disubstituted Tetrahydropyrans and Piperi

ChemInform ◽  
2010 ◽  
Vol 29 (27) ◽  
pp. no-no
Author(s):  
M. G. BANWELL ◽  
B. D. BISSETT ◽  
C. T. BUI ◽  
H. T. T. PHAM ◽  
G. W. SIMPSON
Keyword(s):  
Double Bond ◽  
Michael Addition

Intramolecular Michael Addition of N- and O-Centred Nucleophiles to Tethered Acrylates. The Role of Double-Bond Geometry in Controlling the Diastereo- selectivity of Cyclizations Leading to 2,6-Disubstituted Tetrahydropyrans and Piperidines.

1998 ◽  
Vol 51 (1) ◽  
pp. 9 ◽  
Author(s):  
Martin G. Banwell ◽  
Brett D. Bissett ◽  
Chinh T. Bui ◽  
Ha T. T. Pham ◽  
Gregory W. Simpson
Keyword(s):  
Double Bond ◽  
Total Synthesis ◽  
Michael Addition ◽  
Reductive Amination ◽  
Major Product ◽  
Enantioselective Synthesis ◽  
Cyclization Reactions ◽  
Glandular Secretion

The oxyanion derived from hydroxyacrylate E-(5) undergoes smooth intramolecular Michael addition to give the trans-2,6-disubstituted tetrahydropyran (7) as the major product of reaction. In contrast, the oxyanion obtained from isomer Z-(5) cyclizes to give the cis-2,6-disubstituted tetrahydropyran (6) as the major product. Such chemistry has been extended to the enantioselective synthesis of (+)-(6) the acquisition of which constitutes a formal total synthesis of acid (+)-(2), a constituent of the glandular secretion from the civet cat (Viverra civetta). Reductive amination of keto acrylate (12) affords an intermediate amine which cyclizes, in situ, to give the cis-2,6-disubstituted piperidine (26). Analogous treatment of compound (13) delivers the isomeric trans-2,6-disubstituted piperidine (27) as the exclusive product of reaction. Transition state structures have been proposed to account for the diastereoselectivities observed in all of the cyclization reactions.

Recent Synthetic Approaches and Biological Evaluations of Amino Hexahydroquinolines and Their Spirocyclic Structures

2019 ◽  
Vol 19 (7) ◽  
pp. 875-915 ◽  
Author(s):  
Amr M. Abdelmoniem ◽  
Magda F. Mohamed ◽  
Doaa M. Abdelmoniem ◽  
Said A.S. Ghozlan ◽  
Ismail A. Abdelhamid
Keyword(s):  
Double Bond ◽  
Calcium Channel ◽  
Michael Addition ◽  
Antitubercular Agents ◽  
Sar Studies ◽  
Two Component ◽  
Synthetic Routes ◽  
Synthetic Approaches ◽  
Three Components

In this review, the recent synthetic approaches of amino hexahydroquinolines and their spirocyclic structures were highlighted. The synthetic routes include, two-components, three-components or fourcomponents reactions. The two-component [3+3] atom combination reaction represents the simplest method. It involves Michael addition of the electron rich β-carbon of β-enaminones to the activated double bond of cinnamonitriles followed by cyclization to yield hexahydroquinoline compounds. The bioactivity profiles and SAR studies of these compounds were also reviewed with emphasis to the utility of these substances as antimicrobial, anticancer and antitubercular agents, as well as calcium channel modulators.

Porcine glutathione transferase Alpha 2-2 is a human GST A3-3 analogue that catalyses steroid double-bond isomerization

2010 ◽  
Vol 431 (1) ◽  
pp. 159-167 ◽  
Author(s):  
Natalia Fedulova ◽  
Françoise Raffalli-Mathieu ◽  
Bengt Mannervik
Keyword(s):  
Double Bond ◽  
Glutathione Transferase ◽  
Biological Species ◽  
Glutathione Transferases ◽  
Special Role ◽  
Primary Role ◽  
The Novel ◽  
Protective Function ◽  
Isomerase Activity

A primary role of GSTs (glutathione transferases) is detoxication of electrophilic compounds. In addition to this protective function, hGST (human GST) A3-3, a member of the Alpha class of soluble GSTs, has prominent steroid double-bond isomerase activity. The isomerase reaction is an obligatory step in the biosynthesis of steroid hormones, indicating a special role of hGST A3-3 in steroidogenic tissues. An analogous GST with high steroid isomerase activity has so far not been found in any other biological species. In the present study, we characterized a Sus scrofa (pig) enzyme, pGST A2-2, displaying high steroid isomerase activity. High levels of pGST A2-2 expression were found in ovary, testis and liver. In its functional properties, other than steroid isomerization, pGST A2-2 was most similar to hGST A3-3. The properties of the novel porcine enzyme lend support to the notion that particular GSTs play an important role in steroidogenesis.

ChemInform Abstract: Michael Addition of N-Unprotected 2-Oxindoles to Nitrostyrene Catalyzed by Bifunctional Tertiary Amines: Crucial Role of Dispersion Interactions.

ChemInform ◽  
2014 ◽  
Vol 45 (40) ◽  
pp. no-no
Author(s):  
Christoph Reiter ◽  
Sonia Lopez-Molina ◽  
Bernhard Schmid ◽  
Christian Neiss ◽  
Andreas Goerling ◽  
...  
Keyword(s):  
Michael Addition ◽  
Crucial Role ◽  
Tertiary Amines ◽  
Dispersion Interactions

Enaminones as Building Blocks In Heterocyclic Synthesis: A New One Pot Synthesis of Polyfunctional Substituted Pyridines

2001 ◽  
Vol 56 (10) ◽  
pp. 1074-1078 ◽  
Author(s):  
Samia Michel Agamy ◽  
Mervat Mohammed Abdel-Khalik ◽  
Mona Hassan Mohamed ◽  
Mohammed Hilmy Elnagdi
Keyword(s):  
Acetic Acid ◽  
Double Bond ◽  
Aromatic Aldehyde ◽  
Michael Addition ◽  
Ammonium Acetate ◽  
Building Blocks ◽  
Heterocyclic Synthesis ◽  
One Pot ◽  
Active Methyl ◽  
Substituted Pyridines

Enaminones react with a variety of active methyl and methylene reagents in presence of ammonium acetate to yield functionally substituted pyridines in good yields. The reaction proceeded via initial Michael addition across the double bond followed by cyclization. The reaction of enaminone with aromatic aldehyde in acetic acid/ammonium acetate afforded the dihydropyridine that was oxidized to the corresponding pyridine.

scholarly journals Effects of Several Androgens and Steroid Metabolites on Erythropoietin Production in the Isolated Perfused Dog Kidney

Blood ◽  
1974 ◽  
Vol 43 (1) ◽  
pp. 39-47 ◽  
Author(s):  
Luiz G. Paulo ◽  
Gregory D. Fink ◽  
Byung L. Roh ◽  
James W. Fisher
Keyword(s):  
Double Bond ◽  
Spatial Configuration ◽  
Significant Elevation ◽  
Methyl Group ◽  
Erythropoietin Production ◽  
Dog Kidney ◽  
Isolated Kidneys

Abstract In an attempt to clarify the role of the kidney in the action of several androgens and steroid metabolites on erythropoietin (ESF) production, ESF titers were measured in perfusates of isolated kidneys from dogs previously exposed to 4-hr hypoxia and perfused with blood containing testosterone (Test), 5α-17β-hydroxyandrostan-3-one (5αDHT), 5β-17β-hydroxyandrostan-3-one (5βDHT), 19-nortestosterone (19-nor), oxymetholone (Oxy), fluoxymesterone (Fluoxy), 3α-hydroxy-5β-pregnane, 11,20-dione (3αOH5βpreg), or 3β-hydroxy-5β-pregnane-20-one (3βOH-5 preg). ESF levels in the perfusates were assayed in exhypoxic polycythemic mice. Test, 5αDHT, oxy, fluoxy, and 3βOH5β-preg were found to produce a significant increase in ESF levels in the kidney perfusates. 5βDHT, 19-nor, and 3αOH5βpreg failed to produce a significant elevation in erythropoietin titers in the perfusates of the isolated perfused kidneys. These data suggest that the 4-5 double bond and the spatial configuration of the hydrogen at the 5 position as well as the lack of a methyl group in the 19 position of the basic androstan nucleus are important in the ability of these steroids to stimulate kidney production of ESF.

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