A NEW APPROACH TO MASS-SPECTROMETRY OF OX YGENATED CARBONIC-ACIDS - PYRROLIDIDES

A conventional one-pot procedure is described for the synthesis of pyr rolidides from natural labile carboxylic acids (prostaglandins, epoxy- , hydroxy-, ketoacids) through a mixed anhydride ( isobutylchloroforma te and triethylamine in THF 15 min at -20 degrees C) followed by treat ment with pyrrolidine (10 min at 25 degrees C) and evaporation. The co mpounds obtained gave readily interpretable mass spectra, thus showing that pyrrolidides can be used for the identification of oxygenated na turally occurring carboxylic acids by mass spectrometry.