Efficient Synthesis of Tetrasubstituted Furans and Naphthofurans by Using Nitroallylic Acetates
| Autor: | Huang, Wan-Yun, 黃琬澐 |
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| Rok vydání: | 2011 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 100 Synthesis of polysubstituted furans and naphthofurans represent an important subclass in organic synthesis. Herein, we develop a new synthetic strategy for accessing tetrasubstituted furans by Feist-Bénary type reaction between allylic acetate precursor and 1,3-dicarbonyl/ α-withdrawing ketones. After studying a series of substrate scope under optimized conditions, we provided a reasonable mechanism. In this process, nucleophile attacks to Michael acceptor by SN2’ process, then undergo addition-elimination to give desired aromatic furan compounds（chemical yield up to 96% ）. The use of 1,3-cyclopentandione as starting material, pyran is obtained as major product. On the other hand, use of naphthol as starting material, reaction proceeded through Freidel-Crafts SN2' process followed by intramolecular oxa-Micheal cyclization and subsequently aromatization to give naphthofurans（chemical yield up to 96%）. This method can be applied to different functional groups on allylic acetates, such as electron-donating, electron-withdrawing, heteroaromatic and aliphatic groups. However, when 1-aminonaphthalene was used as the nucleophile, instead of the desired benzoindole, we got SN2 addition compound. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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