Synthesis and properties of zwitterionic phosphonioglycolates

The title compounds are formed from the secondary diphenylphosphane with two or from tertiary phosphanes with one equivalent of glyoxylic acid hydrate in diethyl ether. The diphenylphosphonioglycolate 2 is soluble in D2O with partial solvolysis to 1 whereas the triaryl- or trialkylspecies 3 are highly sensitive to OH or OD compounds. Heating or prolonged storage (over months to years) leads to phosphine oxides 4.