NaIO4-mediated asymmetric bromohydroxylation of alpha,beta-unsaturated carboxamides with high diastereoselectivity: a short route to (-)-cytoxazone and droxidopa

TitleNaIO4-mediated asymmetric bromohydroxylation of alpha,beta-unsaturated carboxamides with high diastereoselectivity: a short route to (-)-cytoxazone and droxidopa
Publication TypeJournal Article
Year of Publication2007
AuthorsGeorge, S, Narina, SV, Sudalai, A
JournalTetrahedron Letter
Volume48
Issue8
Pagination1375-1378
Date PublishedFEB
Type of ArticleArticle
ISSN0040-4039
Keywordsasymmetric bromohydroxylation, Carboxamide, cytoxazone, droxidopa, NaIO4
Abstract

The NaIO4-mediated asymmetric bromohydroxylation of alpha,beta-unsaturated carboxamides was achieved using lithium bromide as the bromine source under acidic conditions at rt to afford the corresponding chiral alpha-bromo-beta-hydroxy carboxamides. Excellent yields (77-90%) and diastereoselectivities (up to 10:1) along with exclusive control over regio- as well as anti-selectivity are the main features with a good scope of substrates. The method has successfully been applied in the enantioselective syntheses of two biologically important molecules, viz (-)-cytoxazone and L-threo-DOPS (droxidopa). (c) 2007 Elsevier Ltd. All rights reserved.

DOI10.1016/j.tetlet.2006.12.109
Type of Journal (Indian or Foreign)Foreign
Impact Factor (IF)2.347
Divison category: 
Chemical Engineering & Process Development