A ceric ammonium nitrate based oxidative cleavage pathway for the asymmetric aldol adducts of oxadiazinones derived from (1 R ,2 S )- N - p -methoxybenzylnorephedrine
| Autor: | Nicole Comas, Jennifer Wilson, Austin R. Leise, Doug Harrison, Eileen G. Whitemiller, Christopher G. Hamaker, Ian Golightly, Shawn R. Hitchcock, Jacob Timms, Dipak Patel |
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| Rok vydání: | 2017 |
| Předmět: |
Chiral auxiliary
010405 organic chemistry Organic Chemistry Absolute configuration Diastereomer 010402 general chemistry 01 natural sciences Medicinal chemistry Reductive amination Catalysis 0104 chemical sciences Adduct Inorganic Chemistry chemistry.chemical_compound Hydrolysis chemistry Aldol reaction Organic chemistry Physical and Theoretical Chemistry Ceric ammonium nitrate |
| Zdroj: | Tetrahedron: Asymmetry. 28:1154-1162 |
| ISSN: | 0957-4166 |
| DOI: | 10.1016/j.tetasy.2017.08.003 |
| Popis: | An N 4 - p -methoxybenzyloxadiazinone has been prepared from (1 R ,2 S )-norephedrine through a process of reductive amination, N-nitrosation, reduction, and cyclization. The oxadiazinone was acylated and employed in the asymmetric aldol addition reaction with aromatic and aliphatic aldehydes to yield aldol adducts in isolated yields ranging from 54% to 90%. Selected aldol adducts were treated with ceric ammonium nitrate in aqueous acetonitrile to afford the desired β-hydroxycarboxylic acids through a tandem process of oxidative cleavage of the N 4 - p -methoxybenzyl group and acidic hydrolysis of the N 3 -acyl side chain. The β-hydroxycarboxylic acids were recovered in high diastereomeric purity as determined by 500 MHz 1 H NMR spectroscopy and the absolute configuration was confirmed by polarimetry. The chiral auxiliary unit, the 3,4,5,6-tetrahydro-2 H -1,3,4-oxadiazin-2-one (oxadiazinone), was converted into its corresponding 3,6-dihydro-2 H -1,3,4-oxadiazin-2-one (oxadiazinone) through an oxidative pathway promoted by the ceric ammonium nitrate. |
| Databáze: | OpenAIRE |
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