Decarboxylated S-adenosyl-L-methionine and its nine analogs have been prepared by a modified method of Jamieson including alkylation of the appropriate aminoalkyl-adenosyl thioether with alkyl iodides in a mixture of formic and acetic acids in the presence of silver perchlorate. The use of silver perchlorate allowed various combinations of the thioether and the alkyl iodide, and prompted the reaction. The sulfonium compounds were obtained as a white hygroscopic powder in 99% ethanol after purification by silica gel column chromatography with a solvent system of butanol-acetic acid-water (1 : 1 : 1). The chemical and physical data of the sulfonium compounds supported a general structure containing 2 mol of sulfuric acid and 0.5 mol of ethanol. The nuclear magnetic resonance data showed the existence of sulfonium diastereoisomers.