4-Spiro[2.n]alkyl cations and their rearrangements
| Autor: | G. K. S. Prakash, T N Rawdah, A P Fung, George A. Olah |
|---|---|
| Rok vydání: | 1987 |
| Předmět: |
Octanol
chemistry.chemical_classification Magnetic Resonance Spectroscopy Multidisciplinary Bicyclic molecule Stereochemistry Chemistry Temperature Carbocation Ring (chemistry) Medicinal chemistry chemistry.chemical_compound Alcohols Cations Ionization Spiro Compounds Superacid Heptanol Alkyl Research Article |
| Zdroj: | Proceedings of the National Academy of Sciences. 84:5092-5095 |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.84.15.5092 |
| Popis: | A series of 4-spiro[2.n]alkanols, where n = 3-7, were ionized in either FSO3H x SbF5/SO2ClF or SbF5/SO2ClF at -78 degrees C and -130 degrees C. The resulting solutions were studied by 13C NMR spectroscopy over the temperature range of -130 degrees C to -10 degrees C. The 4-spiro[2.5]octanol gave the expected static 4-spiro[2.5]octyl cation, which can be considered as a long-lived secondary cyclohexyl cation stabilized by an adjacent spirocyclopropane ring. The same spiro[2.5]octyl cation was also obtained by ionization of isomeric bicyclo[4.2.0]octan-1-ol and bicyclo[4.1.0]heptyl-1-methanol. The static spiro[2.5]-octyl cation was found to rearrange to the equilibrating 1-bicyclo[3.3.0]octyl cation above -10 degrees C. On the other hand, the 4-spiro[2.4]heptanol gave the rearranged 1-methylcyclohexenyl cation. The spiro[2.6]nonanol gave directly the equilibrating 1-bicyclo[4.3.0]nonyl cation. The other 4-spiro[2.n]-alkanols (n = 3 and 7) gave unidentifiable polymeric products. The ionization of 3-spirocyclopropyl-2-norbornanol yields only the rearranged 2-methylbicyclo[3.2.1]oct-3-ene-2-yl cation. |
| Databáze: | OpenAIRE |
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