The Silylalkyne-Prins Cyclization: Stereoselective Synthesis of Tetra- and Pentasubstituted Halodihydropyrans
A new type of Prins cyclization using silylated secondary homopropargylic alcohols and aldehydes yielding tetra- and pentasubstituted dihydropyrans is described. The presence of the trimethylsilyl group in the triple bond favors the Prins cyclization and minimizes the 2-oxonia-[3,3]-sigmatropic rearrangement as a competitive alternative pathway. Ab initio theoretical calculations of the species involved in the rearrangements support the proposed mechanism. The process is highly stereoselective, affording cis-dihydropyran as the only isomer.
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| Main Authors: | , , , |
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| Other Authors: | |
| Format: | artículo biblioteca |
| Language: | English |
| Published: |
American Chemical Society
2006-03-25
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| Subjects: | Theoretical calculations, Alcohols, Rearrangement, Aldehydes, Cyclization, |
| Online Access: | http://hdl.handle.net/10261/212270 http://dx.doi.org/10.13039/501100006280 |
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| Summary: | A new type of Prins cyclization using silylated secondary homopropargylic alcohols and aldehydes yielding tetra- and pentasubstituted dihydropyrans is described. The presence of the trimethylsilyl group in the triple bond favors the Prins cyclization and minimizes the 2-oxonia-[3,3]-sigmatropic rearrangement as a competitive alternative pathway. Ab initio theoretical calculations of the species involved in the rearrangements support the proposed mechanism. The process is highly stereoselective, affording cis-dihydropyran as the only isomer. |
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