Diastereoselective synthesis of nitroso acetals from (S,E)-γ-aminated nitroalkenes via multicomponent [4 + 2]/[3 + 2] cycloadditions promoted by LiCl or LiClO4
| Autor: | Robert Alan Burrow, Vera L. P. Pereira, Leandro Lara de Carvalho |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
pyrrolizidin-3-one
solvent effect Organic Chemistry Acetal Nitroso Full Research Paper lcsh:QD241-441 Chemistry chemistry.chemical_compound lcsh:Organic chemistry chemistry Cascade reaction Ethyl vinyl ether Organic chemistry lcsh:Q tandem reaction Solvent effects lcsh:Science hetero-Diels–Alder reaction chiral heterodiene Two-dimensional nuclear magnetic resonance spectroscopy Heteronuclear single quantum coherence spectroscopy Derivative (chemistry) |
| Zdroj: | Beilstein Journal of Organic Chemistry Beilstein Journal of Organic Chemistry, Vol 9, Iss 1, Pp 838-845 (2013) |
| ISSN: | 1860-5397 |
| DOI: | 10.3762/bjoc.9.96 |
| Popis: | Chiral nonracemic aminated nitroso acetals were synthesized via diastereoselective multicomponent [4 + 2]/[3 + 2] cycloadditions employing new (S,E)-γ-nitrogenated nitroalkenes 5a–c as heterodienes, ethyl vinyl ether (EVE) as a dienophile, and selected electron-deficient alkenes as 1,3-dipolarophiles. The employment of different organic solutions of LiClO4 or LiCl as promoter systems provided the respective nitroso acetals with yields from 34–72% and good levels of diastereoselectivity. In addition, the nitroso acetal 9c was transformed to the pyrrolizidin-3-one derivative 14c, proving the usefulness of the route in the synthesis of an interesting chiral compound. The elucidation of the stereostructures was based on 2D COSY, NOESY and HSQC NMR experiments as well as an X-ray diffraction experiment. |
| Databáze: | OpenAIRE |
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