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6 results on '"John Brennan"'

1. Bioreduction of (R)-carvone and regioselective Baeyer-Villiger oxidations: Application to the asymmetric synthesis of cryptophycin fragment A

Author

John Brennan, Varie David Lee, Milton J. Zmijewski, John Allan Rieck, David A. Hay, Jason S. Cronin, and Barbara Shreve Briggs

Subjects
Carvone, Chemistry, Fragment (computer graphics), Stereochemistry, Organic Chemistry, Enantioselective synthesis, Cyclohexanone, Regioselectivity, Biochemistry, chemistry.chemical_compound, Cryptophycin, Drug Discovery, Stereoselectivity, Enantiomer
Abstract

Cryptophycin fragment A ( 1 ) was prepared in high enantiomeric purity in 10 steps from ( R )-carvone. A stereoselective bioreduction of ( R )-carvone to neodihydrocarveol and a regioselective Baeyer-Villiger oxidation of cyclohexanone 8 with pertrifluoroacetic acid were employed in this synthesis.

Published
1998

2. 4-Fluoroazetidinone derivatives from secopenicillanate sulphonium tetrafluoroborates

Author

John Brennan, Faiq H. S. Hussain, and Pedro Virgili

Subjects
chemistry.chemical_compound, Tetrafluoroborate, Bicyclic molecule, Chemistry, Organic Chemistry, Drug Discovery, Trimethyloxonium tetrafluoroborate, Lactam, Organic chemistry, Imide, Biochemistry
Abstract

Reaction of certain secopenicillanate esters with trimethyloxonium tetrafluoroborate yielded 4-fluoroazetidinone derivatives presumably via the intermediacy of secopenicillanate sulphonium tetrafluoroborate salts.

Published
1986

3. The synthesis of monobactam analogues bearing carbapenemside-chains on C(3)

Author

John Brennan, Stanley M. Roberts, Christopher J. Ashcroft, and Christopher E. Newall

Subjects
biology, Stereochemistry, Organic Chemistry, Biological activity, Biochemistry, chemistry.chemical_compound, chemistry, Drug Discovery, medicine, biology.protein, Side chain, Lactam, Monobactam, medicine.drug, Organic anion, Antibacterial agent
Abstract

A series of monobactam analogues lacking 3-acylamino side chains has been synthesised from the photoisomer of 4-methyl-2-pyridone; none of these analogues showed any useful biological activity.

Published
1984

4. An enantioselective synthesis of loracarbef (LY163892/KT3777)

Author

B. J. Graves, Michael A. Carr, Billy G. Jackson, R. L. Nist, W. C. Vladuchick, C. D. Kochert, Gardner John Paul, D. E. Prather, Michael Dean Kinnick, Christopher W. Doecke, B. D. Boyer, Larry L. Moore, C. A. Bunnell, J. E. Jun. Burks, P. Hines, John Brennan, John Michael Morin, Christina Bodurow, Thomas Michael Eckrich, Wayne Douglas Luke, Fisher Jack Wayne, Richard C. Hoying, D. L. Sparks, and J. S. Lewis

Subjects
Chemistry, medicine.drug_class, digestive, oral, and skin physiology, Organic Chemistry, Antibiotics, Enantioselective synthesis, Carbacephem, Biochemistry, Drug Discovery, polycyclic compounds, medicine, Organic chemistry, Loracarbef, medicine.drug
Abstract

An enantioselective synthesis of the new, orally absorbable, totally synthetic β-lactam antibiotic, loracarbef (LY163892/KT3777) is described.

Published
1989

5. A phosphorane mediated synthesis of tetronic, thiotetronic and tetramic lactones

Author

John Brennan and Patrick J. Murphy

Subjects
chemistry.chemical_classification, Bicyclic molecule, Intramolecular reaction, Chemistry, Stereochemistry, medicine.drug_class, Organic Chemistry, Carboxamide, Thioester, Biochemistry, Phosphorane, chemistry.chemical_compound, Drug Discovery, Wittig reaction, Thiolactone, Lactam, medicine, Organic chemistry
Abstract

Intramolecular reaction of stabilised γ-acylphosphoniumylides derived from esters, thiolesters and amides withγ-lactone carbonyl groups resulted in the formation, by a Wittig-type cyclisation, of tetronic, thiotetronic and tetramic γ-lactones respectively.

Published
1988

6. An efficient synthesis of (±) 7-oxo-3-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate-3,3-dioxide

Author

Pinto Ivan Leo and John Brennan

Subjects
Heptane, Bicyclic molecule, Organic Chemistry, Biochemistry, Medicinal chemistry, Sulfone, chemistry.chemical_compound, chemistry, Intramolecular force, Yield (chemistry), Drug Discovery, Lactam, Organic chemistry, Carboxylate, Carbene
Abstract

The title compound was prepared in good yield via intramolecular insertion of an α-alkoxycarbonyl, α-sulphonyl carbene into the NH bond of an azetidinone.

Published
1983

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