On the Synergism Between H[subscript 2]O and a Tetrahydropyran Template in the Regioselective Cyclization of an Epoxy Alcohol
A regioselective epoxy alcohol cyclization promoted by the combination of neutral water and a tetrahydropyran template was investigated through a series of mechanistic experiments carried out on an epoxy alcohol containing a tetrahydropyran ring (1a) and its carbocyclic congener (1b). In contrast to...
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| Format: | Article |
| Language: | en_US |
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American Chemical Society (ACS)
2013
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| Online Access: | http://hdl.handle.net/1721.1/82097 https://orcid.org/0000-0002-8601-7799 |
| _version_ | 1811092297770598400 |
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| author | Byers, Jeffery A. Jamison, Timothy F. |
| author2 | Massachusetts Institute of Technology. Department of Chemistry |
| author_facet | Massachusetts Institute of Technology. Department of Chemistry Byers, Jeffery A. Jamison, Timothy F. |
| author_sort | Byers, Jeffery A. |
| collection | MIT |
| description | A regioselective epoxy alcohol cyclization promoted by the combination of neutral water and a tetrahydropyran template was investigated through a series of mechanistic experiments carried out on an epoxy alcohol containing a tetrahydropyran ring (1a) and its carbocyclic congener (1b). In contrast to 1a, cyclizations of 1b were unselective and displayed significantly faster reaction rates suggesting that the tetrahydropyran oxygen in 1a is requisite for regioselective cyclization. Reactions for both substrates were shown to occur in solution and under kinetic control without significant influence from hydrophobic effects. Kinetic measurements carried out in water/dimethyl sulfoxide mixtures suggest that 1b reacts exclusively through an unselective pathway requiring one water molecule more than what is required to solvate the epoxy alcohol. Similar experiments for 1a suggest a competition between an unselective and a selective pathway requiring one and two water molecules in excess of those required to solvate 1a, respectively. The selective pathway observed for 1a but not in 1b is rationalized by electronic and conformational differences between the two compounds. |
| first_indexed | 2024-09-23T15:16:06Z |
| format | Article |
| id | mit-1721.1/82097 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T15:16:06Z |
| publishDate | 2013 |
| publisher | American Chemical Society (ACS) |
| record_format | dspace |
| spelling | mit-1721.1/820972022-09-29T13:46:24Z On the Synergism Between H[subscript 2]O and a Tetrahydropyran Template in the Regioselective Cyclization of an Epoxy Alcohol Byers, Jeffery A. Jamison, Timothy F. Massachusetts Institute of Technology. Department of Chemistry Byers, Jeffery A. Jamison, Timothy F. A regioselective epoxy alcohol cyclization promoted by the combination of neutral water and a tetrahydropyran template was investigated through a series of mechanistic experiments carried out on an epoxy alcohol containing a tetrahydropyran ring (1a) and its carbocyclic congener (1b). In contrast to 1a, cyclizations of 1b were unselective and displayed significantly faster reaction rates suggesting that the tetrahydropyran oxygen in 1a is requisite for regioselective cyclization. Reactions for both substrates were shown to occur in solution and under kinetic control without significant influence from hydrophobic effects. Kinetic measurements carried out in water/dimethyl sulfoxide mixtures suggest that 1b reacts exclusively through an unselective pathway requiring one water molecule more than what is required to solvate the epoxy alcohol. Similar experiments for 1a suggest a competition between an unselective and a selective pathway requiring one and two water molecules in excess of those required to solvate 1a, respectively. The selective pathway observed for 1a but not in 1b is rationalized by electronic and conformational differences between the two compounds. Petroleum Research Fund (47212-AC1) 2013-11-13T14:42:04Z 2013-11-13T14:42:04Z 2009-04 2009-01 Article http://purl.org/eprint/type/JournalArticle 0002-7863 1520-5126 http://hdl.handle.net/1721.1/82097 Byers, Jeffery A., and Timothy F. Jamison. “On the Synergism Between H2O and a Tetrahydropyran Template in the Regioselective Cyclization of an Epoxy Alcohol.” Journal of the American Chemical Society 131, no. 18 (May 13, 2009): 6383-6385. https://orcid.org/0000-0002-8601-7799 en_US http://dx.doi.org/10.1021/ja9004909 Journal of the American Chemical Society Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Chemical Society (ACS) PMC |
| spellingShingle | Byers, Jeffery A. Jamison, Timothy F. On the Synergism Between H[subscript 2]O and a Tetrahydropyran Template in the Regioselective Cyclization of an Epoxy Alcohol |
| title | On the Synergism Between H[subscript 2]O and a Tetrahydropyran Template in the Regioselective Cyclization of an Epoxy Alcohol |
| title_full | On the Synergism Between H[subscript 2]O and a Tetrahydropyran Template in the Regioselective Cyclization of an Epoxy Alcohol |
| title_fullStr | On the Synergism Between H[subscript 2]O and a Tetrahydropyran Template in the Regioselective Cyclization of an Epoxy Alcohol |
| title_full_unstemmed | On the Synergism Between H[subscript 2]O and a Tetrahydropyran Template in the Regioselective Cyclization of an Epoxy Alcohol |
| title_short | On the Synergism Between H[subscript 2]O and a Tetrahydropyran Template in the Regioselective Cyclization of an Epoxy Alcohol |
| title_sort | on the synergism between h subscript 2 o and a tetrahydropyran template in the regioselective cyclization of an epoxy alcohol |
| url | http://hdl.handle.net/1721.1/82097 https://orcid.org/0000-0002-8601-7799 |
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