Oxonium Ion Mediated Synthesis of 4-Substituted Spiro-Isoxazolines.
Tetrahedron Lett
; 50(5): 533-535, 2009 Feb 04.
Article
em En
| MEDLINE
| ID: mdl-20140060
ABSTRACT
The stereoselective synthesis of 4-bromo-spiro-isoxazolines was achieved in one step through the bromination of various isoxazoles that contain a pendant alcohol or carboxylic acid functional group. Isoxazole bromination leads to a bromonium ion intermediate which opens either by neighboring oxygen lone pair electrons or by intramolecular nucleophilic attack. Single X-ray crystal data provides evidence that the two contiguous stereocenters of the spiro-isoxazoline are formed by the anti intramolecular attack of the nucleophile relative to bromine since there is an anti stereochemical relationship between the spirocyclic ring oxygen and the bromine atom.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Tetrahedron Lett
Ano de publicação:
2009
Tipo de documento:
Article