| Autor: |
Seigo Okugawa, Kei Takeda, Hyuma Masu, Kentaro Yamaguchi |
| Rok vydání: |
2005 |
| Předmět: |
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| Zdroj: |
The Journal of organic chemistry. 70(25) |
| ISSN: |
0022-3263 |
| Popis: |
[reactions: see text] The reaction of delta-silyl-gamma,delta-epoxypentanenitrile derivatives 9-12 with a base and an alkylating agent affords (Z)-delta-siloxy-gamma,delta-unsaturated pentanenitrile derivatives via a tandem process that involves the formation of a cyclopropane derivative by epoxy nitrile cyclization followed by Brook rearrangement and an anion-induced cleavage of the cyclopropane ring. Exclusive formation of a (Z)-derivative from trans-epoxides is explained by the reaction pathway that involves a backside displacement of the epoxide by the alpha-nitrile carbanion and the O-Si bond formation followed by concerted processes involving Brook rearrangement and the anti-mode of eliminative ring fission of the cyclopropane from the rotamer 19. The fact that (E)-isomers are exclusively obtained from cis-epoxides and alpha-cyclopropyl-alpha-silylcarbinol derivative 26 provides experimental support for the proposed pathway. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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