Synthesis and elimination reactions of methylsulfonium ions formed from styrene oxide and methylthio compounds related to methionine and cysteine.

Methylsulfonium compounds were prepared through the nucleophilic addition of a number of methylthio reagents to styrene oxide. In the absence of water, methylsulfonium ions from styrene oxide were converted to 2-hydroxy-1-methylthio-1-phenylethane (I) and 1-hydroxy-2-methylthio-1-phenylethane (II) by brief heating. In the presence of water, the glycol 1,2- dihydroxyphenylethane (III) was obtained along with I and II. The addition and elimination reactions were combined in sequences that were carried out in an organic solvent (acetone) or in aqueous solutions containing acetone or methanol. With L-methionine as the reagent, both reactions proceeded in sequence at 37 degrees C in water/methanol (80:20) to give I, II, and III as reaction products. These methods can be used to prepare the methylthio metabolites of styrene oxide.