Regioselective Synthesis of 2-Trimethylsilyl-4H-pyran-4-ones from 1-Ethoxy(hydroxy)-5-(trimethylsilyl)pentenynones |
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| Authors: | Dr Alena S Pankova Dr Pavel Golubev Ilia A Molin Dr Nikolai V Rostovskii |
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| Institution: | Institute of Chemistry, Saint Petersburg State University, 198504 Saint Petersburg, Russia |
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| Abstract: | Exclusive formation of 5-aryl-2-trimethylsilyl-4H-pyran-4-ones is accomplished by a regioselective cyclization of 2-aryl-1-ethoxy(hydroxy)-5-(trimethylsilyl)pent-1-en-4-yn-3-ones. This cyclization occurs in a 6-endo-dig mode through addition to the β-atom of the TMS substituted triple bond. The reaction was found to be general for a range of ethoxyenynones upon heating in glacial acetic acid and for analogous hydroxyenynones in diphenyl ether. Plausible mechanistic explanation and possible post-modifications of resulting pyranones are offered. |
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| Keywords: | cyclization enynone pyran-4-one synthetic methods |
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