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http://hdl.handle.net/11375/17434
Title: | Some Reactions at the C-7 Position of Norbornenes |
Authors: | Clark, Ferrers Robert Scougall |
Advisor: | Warkentin, J. |
Department: | Chemistry |
Keywords: | organolithium, reactions, C-7, Norbornenes, |
Publication Date: | Feb-1972 |
Abstract: | <p> The addition reaction between bicyclo[2.2.1]hept-2-en-7-one and several organolithium reagents was investigated. Saturated alkyllithium reagents, like most Grignard reagents, were shown to add preferentially to the syn-face of the ketone, while unsaturated alkyllithium reagents add preferentially to the anti-face. These results have been rationalized in terms of bimolecular attack by the former reagents and unimolecular attack by the latter reagents.</p> <p> The 7-t-butylbicyclo[2.2.1]hept-2-en-7-cation was shown to rearrange in mildly acidic media to a cation which lost a proton to yield syn-7-methyl-7-(2'-propenyl)bicyclo[2.2.1] hept-2-ene. The formation of this product can be explained by a Wagner-Meerwein migration which proceeds with retention of configuration about the C-7 cation centre.</p> <p> A series of 7-R-bicyclo[2.2.1]hept-2-en-7-radicals were allowed to abstract hydrogen from tri-n-butylstannane. When R = CH3, i-C3H7, n-C4H9, neopentyl, no stereochemical preference for syn- or anti- abstraction was observed. When R = t-C4H9, a large preference was shown for abstraction to occur on the anti-face, while when R = C6H5, syn-abstraction predominated. These observations, in the light of observations of abstraction by the bicyclo[2.2.1]hept-2-en-7-radical, are consistent with homoallylic participation of the double bond at the radical centre of the latter species. </p> |
URI: | http://hdl.handle.net/11375/17434 |
Appears in Collections: | Open Access Dissertations and Theses |
Files in This Item:
File | Description | Size | Format | |
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Clark_Ferrers_R.S._1972:02_Ph.D..pdf | 4.45 MB | Adobe PDF | View/Open |
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