The IR spectra (obtained on a" Specord-75" spectrophotometer in KBr pellets) of the ammonia salts of the alkylthioproprionic acids show broad and intense absorption maxima at 3300-2500 cm-1 (Vort), as well as at 1710 cm-1 (Vo-o), and at 1300-1140 cm-1 (C--<)--H group oscillation); the double bond was absent. Condensation of hexanethiol with the potassium salt of methacrylic acid occurred in the same manner to give the compound ...