ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Selective Acylations of Anions of 3-Isobutoxy-2-cycloalken-l-ones

P. Hrnčiar and J. Šraga

Department of Organic Chemistry, Faculty of Natural Sciences, Comenius University, SK-842 15 Bratislava

Abstract: A new method for synthesis of 5-acyl-3-isobutoxy-2-cyclopenten-1-ones and 6-acyl-3-isobutoxy-2-cyclohexen-1-ones from corresponding 3-isobutoxy-2-cyclopenten-1-one and 3-isobutoxy-2-cyclohexen-1-one was developed. The key step involved a selective deprotonation at the α´-position of the starting 3-alkoxy enones accomplished by two equivalents of lithium diisopropylamide at low temperature. Acylation of the obtained enolates with ethyl chloroformate, 5-ethoxycarbonylpentanoyl chloride, and benzoyl chloride led to the desired products in high yields and selectivity.

Full paper in Portable Document Format: 515a286.pdf

Chemical Papers 51 (5) 286–288 (1997)