Abstract
The NaIO4-mediated asymmetric bromohydroxylation of α,β-unsaturated carboxamides was achieved using lithium bromide as the bromine source under acidic conditions at rt to afford the corresponding chiral α-bromo-β-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).
Original language | English (US) |
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Pages (from-to) | 1375-1378 |
Number of pages | 4 |
Journal | Tetrahedron Letters |
Volume | 48 |
Issue number | 8 |
DOIs | |
State | Published - Feb 19 2007 |
Bibliographical note
Funding Information:S.G. and N.V.S. thank CSIR, New Delhi, for the award of research fellowships. The authors are thankful to Dr. B. D. Kulkarni, Deputy Director, for his support and encouragement.
Keywords
- Asymmetric bromohydroxylation
- Carboxamide
- Cytoxazone
- Droxidopa
- NaIO