Hypervalent Iodine-Mediated Fragmentation of Tertiary Cyclopropanol Systems
| Autor: | Hiroko Kakuda, Masayuki Kirihara |
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| Rok vydání: | 2004 |
| Předmět: | |
| Zdroj: | Journal of Synthetic Organic Chemistry, Japan. 62:919-928 |
| ISSN: | 1883-6526 0037-9980 |
| DOI: | 10.5059/yukigoseikyokaishi.62.919 |
| Popis: | The reaction of tertiary cyclopropanol systems with hypervalent iodines in a protic solvent caused oxidative bond cleavage at C1-C2 and C2-C3 leading to alkenoic acids or their corresponding esters in high yields. In the cases of the compounds bearing an alkyl group on the cyclopropane-ring, the endo-compound gave only the (Z) -alkene while the exo-compound afforded only the (E) -alkene. A strong acid catalyst promoted these reactions. In fluorinated alcohols, the oxidation of cyclopropanol systems with phenyliodine (III) diacetate caused a mixture of enones and β-acetoxyketones. On the other hand, phenyliodine (III) bistrifluoroacetate afforded alkenoic esters. The asymmetric synthesis of (-) -pinidine and its enantiomer was achieved by starting from norgranatanone via the asymmetric enolization, stereoselective cyclopropanation, and ring cleavage of the resulting cyclopropanol system with a hypervalent iodine as key steps. Formal asymmetric synthesis of (+) -indolizidine 223 AB was also accomplished. |
| Databáze: | OpenAIRE |
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