SYNTHESIS OF [C-11] METHYL KETONES VIA [C-11] METHYLATION OF DITHIANEINTERMEDIATES

A versatile synthetic route to obtain [C-11]methyl ketones from aldehy des is described. Test reactions with [C-11]CH3I on the model compound s 2-methyl- and 2-cyclohexyl- 1,3-dithiane followed by oxidation with N-bromosuccinimide gave almost quantitative radiochemical yields. Reac tion of [C-11]CH3I with 2-phenylethyl-1,3-dithiane yielded the corresp onding [C-11]methyl ketone in 80% radiochemical yield together with an unidentified side-product on oxidation with N-bromosuccinimide.