Synthesis of [C-11]methyl ketones via [C-11]methylation of dithiane intermediates

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