Search

Your search keyword '"White AH"' showing total 1,203 results
Start Over Author "White AH"
1,203 results on '"White AH"'

1. Synthesis of 2-acetyl-5-(1,2,3,4,5,6-hexahydroxyhexyl)thiazoles

Author

Ung, AT, Pyne, SG, Jeoffreys, GR, Skelton, BW, White, AH, Ung, AT, Pyne, SG, Jeoffreys, GR, Skelton, BW, and White, AH

Abstract

The syntheses of two diastereoisomers of 2-acetyl-5-(1,2,3,4,5,6- hexahydroxyhexyl)thiazole are reported. The synthesis of these diastereoisomers involved the coupling of 5-metallated 2-(1,1-dimethoxyethyl)thiazole with a Weinreb amide derived from d-gluconolactone, followed by asymmetric reduction of the ketone thus prepared. The stereochemistries and structures of some key compounds were determined by single-crystal X-ray structural analysis. © 2011 Springer-Verlag.

Published
2011

2. Intramolecular versus intermolecular oxidative couplings of ester tethered di-aryl ethers

Author

Taylor, SR, Ung, AT, Pyne, SG, Skelton, BW, White, AH, Taylor, SR, Ung, AT, Pyne, SG, Skelton, BW, and White, AH

Abstract

The oxidative cyclization of 3,4-dimethoxyphenyl 3,4-dimethoxyphenylacetate, through intramolecular biphenyl bond formation, was successful and gave the target seven-membered lactone in good yield (85-86%). All other ester substrates gave biphenyl products or their further oxidized products via intermolecular coupling of their radical cation intermediate with the neutral substrate. It appears that matching of the oxidation potentials and nucleophilicity of the two phenyl rings, the positioning of the ring substituents and the ease of E to Z isomerization about the ester C-O bond are important factors contributing to these product outcomes. Crown Copyright © 2007.

Published
2007

3. Syntheses of spiro[cyclopropane-1,3′-oxindole]-2-carboxylic acid and cyclopropa[c]quinoline-7b-carboxylic acid and their derivatives

Author

Yong, SR, Ung, AT, Pyne, SG, Skelton, BW, White, AH, Yong, SR, Ung, AT, Pyne, SG, Skelton, BW, and White, AH

Abstract

The synthesis of spiro[cyclopropane-1,3′-oxindole]-2-carboxylic acid, including novel 3-(2- and 3-pyridyl)-substituted analogues and the novel cyclopropa[c]quinoline-7b-carboxylic acid and their ester and amide derivatives is described. These syntheses involve diastereoselective cyclopropanation reactions of methyl 2-(2-nitrophenyl)acrylate and (3E)-(pyridin-2-ylmethylene)- and (3E)-(pyridin-3-ylmethylene)-1,3-dihydro-2H-indol-2-one with ethyl (dimethyl sulfuranylidene) acetate (EDSA). The synthesis of methyl cyclopropa[c]quinoline-7b-carboxylate involves a regioselective reductive cyclization of a nitro-diester precursor. The relative stereochemistry of key compounds has been determined by single-crystal X-ray structural analysis. © 2006.

Published
2007

6. Stemocurtisine, the first pyrido[1,2-a]azapine Stemona alkaloid

Author

Mungkornasawakul, P, Pyne, SG, Jatisatienr, A, Supyen, D, Lie, W, Ung, AT, Skelton, BW, White, AH, Mungkornasawakul, P, Pyne, SG, Jatisatienr, A, Supyen, D, Lie, W, Ung, AT, Skelton, BW, and White, AH

Abstract

A new pentacyclic stemona alkaloid, stemocurtisine (2), with a novel pyrido [1,2-a]azapine A,B-ring system, has been isolated from a root extract of Stemona curtisii. The structure and relative stereochemistry was determined by spectral data interpretation and X-ray crystallography.

Published
2003

7. Magnetic resonance imaging of a thoracic intraspinal synovial cyst

Author

DeLong Wb, White Ah, Gamburd Rs, Kaiser Ja, and Fritz Rc

Subjects
musculoskeletal diseases, Nerve root, Facet joint, Lesion, medicine, Back pain, Synovial cyst, Humans, Orthopedics and Sports Medicine, Rib cage, medicine.diagnostic_test, business.industry, Nerve Compression Syndromes, Laminectomy, Magnetic resonance imaging, Anatomy, Middle Aged, Thorax, Magnetic Resonance Imaging, medicine.anatomical_structure, Synovial Cyst, Female, Spinal Diseases, Neurology (clinical), medicine.symptom, Synovial membrane, business, Spinal Nerve Roots
Abstract

A 50-year-old woman presented with mid-thoracic back pain that radiated to the left rib cage in a radicular manner. Magnetic resonance imaging revealed an extradural mass compressing the left T9 nerve root. The mass was adjacent to a degenerated T9-10 facet joint with an enhancing low signal intensity rim. Recognition of the characteristic imaging findings of an intraspinal synovial cyst resulted in the correct preoperative diagnosis despite the unusual location of this lesion at T9-10.

Published
1994

8. The Use of Selective Nerve Root Blocks: Diagnostic, Therapeutic, or Placebo?

Author

Wetzel Ft, Paul J. Slosar, and White Ah

Subjects
Radicular Syndrome, medicine.medical_specialty, Spinal injections, Nerve root, business.industry, Placebo, Low back pain, Surgery, law.invention, Randomized controlled trial, law, Spinal nerve, Anesthesia, Medicine, Orthopedics and Sports Medicine, Neurology (clinical), medicine.symptom, business
Abstract

An increasing number of therapeutic spinal injections are performed each year despite little validation in randomized controlled trials. Additional injections are performed for diagnostic purposes of localizing symptomatic nerve roots, again without detailed evaluation of accuracy, specificity, or sensitivity. Drs. Slosar and White argue that selective nerve root blocks are extremely useful; Dr. Wetzel believes that selective nerve root blocks have no role in selecting patients for surgery. Scott D. Boden, MD Robert F. McLain, MD Associate Editors; Spine Controversies

Published
1998
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results