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

Methylation of 1,3-cyclopentanedione, 1,3-cyclohexanedione, and 1,3-cycloheptanedione with iodomethane in aprotic solvents in the absence and in the presence of 18-crown-6

J. Šraga and P. Hrnčiar

Department of Organic Chemistry, Faculty of Natural Sciences, Komenský University, 816 31 Bratislava

Abstract:  Anions of 1,3-cyclopentanedione, 1,3-cyclohexanedione, and 1,3-cyclohep­tanedione were methylated with iodomethane in aprotic solvents. It was found that the highest amount of О-derivative was formed in nonpolar solvents (diethyl ether, tetrahydrofuran). The presence of 18-crown-6 did not affect the C/O ratio of methylation of the investigated 1,3-cycloalkanedione anions significantly. The reasons for different solvent effects on the C/O ratio of alkylation of cyclic and acyclic 1,3-dicarbonyl compounds are discussed.

Full paper in Portable Document Format: 351a119.pdf

Chemical Papers 35 (1) 119–126 (1981)