Synthesis of l,2-dihydro-3H-pyrrolo[1,2-a]pyrrole-1-carboxylic acids and homologous pyridine and azepine analogues thereof
| Autor: | O. Halpern, T. Craig Thurber, Albert R. Van Horn, Michael L. Maddox, Humberto Carpio, Robert Greenhouse, J. Ackrell, Fidencio Franco, Diane Cho, Y. Antonio, Derek Tegg, Angel Guzman, Doug Wren, Richard Koehler, Anthony Prince, Virginia Perez, Raquel Salas, Esperanza Velarde, Edvige Galeazzi, Alicia Leon, Joseph M. Muchowski, David Valdés, P. Gallegra |
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| Rok vydání: | 1982 |
| Předmět: | |
| Zdroj: | Canadian Journal of Chemistry. 60:2295-2312 |
| ISSN: | 1480-3291 0008-4042 |
| DOI: | 10.1139/v82-328 |
| Popis: | Several syntheses of the previously unknown 1,2-dihydro-3H-pyrrolo[1,2-a]pyrrole-1-carboxylic acid and various 5- and 6-substituted derivatives thereof have been devised. Some of these processes have been extended to the heretofore unreported 5,6,7,8-tetrahydropyrrolo[1,2-a]pyridine-8-carboxylic acid and 5,6,7,8-tetrahydro-9H-pyrrolo[1,2-a]azepine-9-carboxylic acid derivatives.Two new processes were developed for the conversion of pyrroles into the corresponding pyrrol-2-acetic acid esters. Both processes were based on the use of the readily available ethoxalylpyrrole derivatives as the starting material. One sequence involved saponification of the α-keto ester, followed by Wolff–Kishner reduction of the crude α-keto acid salt and subsequent esterification of the acetic acid derivative thus produced. The second synthesis commenced with reduction of the 2-ethoxalpyrrole with sodium borohydride to the α-hydroxy ester, which was further reduced to the acetic acid ester with an equimolar mixture of triphenylphosphine and triphenylphosphine diiodide. |
| Databáze: | OpenAIRE |
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