MASS-SPECTRA OF METHYLPYRANOSIDES OF N-AC ETYL MONOAMINO AND DIAMINO SUGAR ACETATES

Mass spectra of O-acetylated methyl 4-, 6-acetamido- and 3,4- 2,4-, 2, 3-diacetamido pyranosides are reported. Their EI fragmentations are de scribed in terms of a hypothetical function of the energy distribution for five different types of molecular ions, thus conforming the posit ions of the acetamido groups. Due to the similarity in the electronic properties of OMe and NHAc groups, which induce high rate cleavage of alpha-C-C bonds, resemblance of the fragmentation patterns of acetylat ed and methylated glycosides is also revealed.