Synthesis of N-tetrahydropyranyl-S-methylmethioninesulfonium salts
D,L-Methionine reacts in alkaline medium with 4-methyl-3,4-epoxytetrahydropyran via the amino group to form, in accordance with the Krasusskii rule, an oxirane ring opening product, namely N-(4-hydroxy-4-methyl-3-tetrahydropyranyl)-D,L-methionine. N-(4-Hydroxy-4-methyl-3-tetrahydropyranyl)-S-methylmethioninesulfonium salts are synthesized in high yields by methylating the latter then treating it with organic or inorganic acids.