Mass spectra of 4-acylamino-3-hydroxy(or acyloxy) thiophans

The mass spectra of cis- and trans-4-acylamino-3-hydroxy(or acyloxy)thiophans were investigated. The general principles of fragmentation under the influence of electron impact were established. A difference in the intensities of the peaks of the fragments formed at an ionizing-electron energy of 14 eV was observed for some of the cis and trans isomers of 3,4-substituted thiophans.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 466–471, April, 1976.