ORGN 571 |
| A practical one-pot synthesis of 5-carbonylmethyl-1,2,4-oxadiazoles from amidoximes under solvent-free conditions was developed. Reaction of amidoximes and malonic diesters under solvent-free conditions gave alpha-1,2,4-oxadiazolo esters. Reaction of amidoximes and alpha-keto esters under similar conditions gave 5-ketomethyl-1,2,4-oxadiazoles. The ester from a bulky alcohol is more reactive than those from less hindered alcohols. Thus a t-butyl ester reacted selectively in the presence of a methyl ester. It is likely that these reactions go through a ketene intermediate generated by elimination of a molecule of alcohol. Experimental details of this transformation and extension of this methodology to a broader scope of substrates will be presented. |
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New Reactions and Methodology, Heterocycles and Aromatics, Bioorganic Chemistry
8:00 PM-10:00 PM, Tuesday, 12 September 2006 Moscone Center -- Hall D, Poster
Division of Organic Chemistry |