ORGN 605 |
| David E. Lewis and Grant J. Sormunen. Department of Chemistry, University of Wisconsin - Eau Claire, Eau Claire, WI 54702 |
| First reported in 1900, the Grignard reaction is a modification of the earlier Barbier reaction, in which the alkyl halide and carbonyl compound were heated together with magnesium under an inert atmosphere. Subsequently, Barbier and Grignard found that the presence of ether as a solvent accelerated the reaction dramatically. When one is dealing with reactive alkyl halides, the Wurtz coupling of the alkyl halide often becomes a major reaction. This is especially true for allyl and benzyl halides: allylmagnesium bromide, for example, must be formed at low temperature and under conditions of low concentration to avoid the formation of 1,5-hexadiene as the major, or even sole product of the reaction. We have found that the Barbier-Grignard reaction between allyl bromide and carbonyl compounds is an especially convenient method for the synthesis of homoallylic alcohols, but that this reaction is limited in that it fails with benzyl halides and with nitriles. The scope and limitations of the reaction will be discussed. |
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New Reactions, Methodology, Heterocycles, Aromatics
8:00 PM-10:00 PM, Wednesday, August 25, 2004 Pennsylvania Convention Center -- Hall D, Poster
Division of Organic Chemistry |