| Autor: |
Paul G. Gassman, Sang-Don Han, Leonard J. Chyall |
| Rok vydání: |
1998 |
| Předmět: |
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| Zdroj: |
Tetrahedron Letters. 39:5459-5462 |
| ISSN: |
0040-4039 |
| DOI: |
10.1016/s0040-4039(98)01110-1 |
| Popis: |
Derivatives of trans -bicyclo[4.1.0]hept-3-ene with chlorine and bromine substituents the 7 position were synthesized and their thermal rearrangements were examined. Thermolysis of the dichloride leads to the formation of the cis-fused isomer, while heating the dibromide results in ring-expanded products. Thermal rearrangement of the bromochloro derivative provided a mixture of ring-isomerized and ring-expanded products. The halogenated compounds are very labile relative to the unsubstituted molecule with rate accelerations on the order of 1000 or more at 120 °C. When solvents of widely varying polarity were employed, the isomerization rate coefficients for the halogenated derivatives vary by a factor of 1.0–3.2. Therefore, it is unlikely that these compounds rearrange via ionic intermediates. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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