KETALIZATIONS OF ARYL OMEGA-(2-IMIDAZOLYL)ALKYL KETONES BY GLYCEROL AND 3-MERCAPTO-1,2-PROPANEDIOL - SYNTHESIS AND CHARACTERIZATION OF YL-2-[OMEGA-(2-IMIDAZOLYL)ALKYL](1,3-DIOXOLAN-4-YL AND 1,3-OXATHIOLAN-5-YL))METHANOL AND YL-2-[OMEGA-(2-IMIDAZOLYL)ALKYL](1,3-DIOXOLAN-4-YL AND 1,3-OXATHIOLAN-5-YL))METHANOL .1.

Aryl 2-[(2-imidazolyl)ethyl or 3-(2-imidazolyl)propyl]ketones were ket alized by glycerol or 3-mercapto-1,2-propanediol in boiling benzene in the presence of 4-toluenesulfonic acid to provide the title compounds . The aryl substituents are 4-chloro-, 4-bromo-, 4-fluoro-, or 2,4-dic hlorophenyl. While aryl (2-imidazolyl)methyl ketones condensed with gl ycerol to form cis- and dazolyl)methyl]-4-(hydroxymethyl)}-1,3-dioxola nes, related condensations with 3-mercapto-1,2-propanediol, under simi lar, or even more stringent reaction conditions, produced no 1,3-oxath iolane analogs, with the starting ketones being recovered. Separation and structure determination of these racemic cis and trans isomeric pr oducts are described. The structure of these stereoisomers was establi shed by means of H-1 and C-13 nmr correlation and nOe experiments. Sel ective methylation of the N-unsubstituted 2-imidazolyl alcohols with o ne equivalent sodium hydride and methyl iodide provided the correspond ing N-methyl alcohols in excellent yields. With excess benzoyl chlorid e, N-unsubstituted 2-imidazolyl alcohols were initially converted to O ,N-dibenzoates from which the N-benzoyl group was easily cleaved by am monium hydroxide in ethanol to provide benzoate esters.