Mass spectra of 4‐substituted‐1,2,6‐trimethyl‐3,5‐diethoxycarbonyl‐1,4‐dihydropyridines

The mass spectra of 4-substituted-1,2,6-trimethyl-3,5-diethoxycarbonyl-1,4-dihydropyridines have been studied. The detailed fragmentation mechanisms, supported by high resolution measurements, the study of metastable ions and the use of deuterium labelling, are discussed.