ORGN 98 |
| Phil Ho Lee and Kooyeon Lee. Department of Chemistry, Kangwon National University, Hyoja-2-dong, Chunchon, Kangwondo, 200-701, South Korea |
| 3-tert-Butyldimethylsilyloxyalk-2-enylsulfonium salts, generated in situ from the reaction of a,b-enones with dimethyl sulfide in the presence of TBSOTf, underwent a novel nucleophilic substitution with allylindiums to give silyl enol ethers of d,e-alkenyl ketones in good yields, which correspond to formal Michael addition products. In a similar manner, 1,4-propargylation of propargylindiums onto the sulfonium salts produced the corresponding silyl enol ethers of d,e-alkynyl ketones in good yields. Organoindium reagents derived from g-substituted propargyl bromide and indium afforded the corresponding silyl enol ethers of b-allenyl ketones in good yields. The reaction proceeds via an addition-substitution mechanism involving the formation of allylic sulfonium salts. The presence of the intermediate sulfonium salt was confirmed by the observation of the low temperature 1H NMR. |
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New Reactions and Methodology, Metal-Mediated Reactions, Heterocycles and Aromatics
8:00 PM-10:00 PM, Sunday, March 28, 2004 Anaheim Convention Center -- Hall A, Poster
Division of Organic Chemistry |