Brønsted acid-catalyzed cycloisomerization of but-2-yne-1,4-diols with or without 1,3-dicarbonyl compounds to tri- and tetrasubstituted furans
A Brønsted acid-catalyzed method to prepare tri- and tetrasubstituted furans efficiently from cycloisomerization of but-2-yne-1,4-diols with or without 1,3-dicarbonyl compounds is described. By taking advantage of the orthogonal modes of reactivity of the alcoholic substrate through slight modificat...
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| Main Authors: | , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | English |
| Published: |
2013
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| Subjects: | |
| Online Access: | https://hdl.handle.net/10356/96148 http://hdl.handle.net/10220/17133 |
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| Institution: | Nanyang Technological University |
| Language: | English |
| Summary: | A Brønsted acid-catalyzed method to prepare tri- and tetrasubstituted furans efficiently from cycloisomerization of but-2-yne-1,4-diols with or without 1,3-dicarbonyl compounds is described. By taking advantage of the orthogonal modes of reactivity of the alcoholic substrate through slight modification of the reaction conditions, a divergence in product selectivity was observed. At room temperature, p-TsOH·H2O-mediated tandem alkylation/cycloisomerization of the propargylic 1,4-diol with the β-dicarbonyl compound was found to selectively occur to provide the tetrasubstituted furan product. On the other hand, increasing the reaction temperature to 80 °C was discovered to result in preferential p-TsOH·H2O-catalyzed dehydrative rearrangement of the unsaturated alcohol and formation of the 2,3,5-trisubstituted furan adduct. |
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