High purity isotopically labeled phosphonic acid esters can be obtained from isotopically enriched Chloro[
13
C]methyl phenyl sulfide The labeled phosphonic acid esters can then be used as precursors for the one step production of labeled vinyl sulfides, labeled vinyl sulfoxides, and labeled vinyl sulfones. The labeled phosphonic acid esters can also be reacted with a variety of aldehydes to produce extended vinyl systems that are isotopically labeled.