Chiral N-Acyloxazolidines: Synthesis, Structure, and Mechanistic Insights
| Autor: | Pedro Cintas, Esther M. S. Pérez, José L. Jiménez, Martin Avalos, Mark E. Light, Juan C. Palacios, Reyes Babiano |
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| Rok vydání: | 2007 |
| Předmět: |
Models
Molecular Oxazolidine Magnetic Resonance Spectroscopy Molecular Structure Rotation Stereochemistry Organic Chemistry Imine Iminium Stereoisomerism Crystal structure Crystallography X-Ray Chemical synthesis chemistry.chemical_compound chemistry Molecule Imines Oxazoles Conformational isomerism Schiff Bases Derivative (chemistry) |
| Zdroj: | The Journal of Organic Chemistry. 73:661-672 |
| ISSN: | 1520-6904 0022-3263 |
| Popis: | A series of chiral imines derived from 1-amino-1-deoxyalditols such as d-glucamine, a rather unexplored raw material from the chiral pool, have been serendipitiously transformed into a novel family of N-acetyl-1,3-oxazolidines by means of an unexpected acetylation. The structure of these substances is supported by spectroscopic and crystallographic data. The acetylates also trigger a complex dynamic transformation, in which an initially configured trans oxazolidine converts into a more stable cis-configured derivative. Both isomers can also exist as rotational conformers (E,Z) as a consequence of the restricted rotation around the N-acetyl bond. The barriers to rotation have been determined by variable-temperature experiments. Overall, this transformation most likely involves the intermediacy of a chiral iminium ion, which has been documented in the synthesis of nitrogen heterocycles, thus explaining the experimental facts. |
| Databáze: | OpenAIRE |
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