The mass spectrometry of kaurene derivatives—II: Kaurenolides and related systems

The mass spectra of a number of natural (II, IV, XII) and modified kaurenolides (I, III, V to XI) are reported. The major fragmentations of these compounds occur by rupture of the ring B to give fragments B and C, both of which contain the ring A. In the case of the 7-hydroxycompounds (II and III) their mass spectra are markedly different due to the difference in configuration at C₇.     

Synthesis of deuterated methyl 2,3,4,6-Tetra-o-methyl-β-d-galactopyranosides

Conclusions We have synthesized methyl 2,3,4,6-tetra-O-methyl--D-galactopyranosides selectively labeled with deuterium in positions 1–6 with deuterium content >90%.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 192–195, January, 1978.     

Determination of the sequence of monosaccharide units in acetates of N-arylglycosylamines of oligosaccharides

Conclusions It was shown for the mass spectra of acetates of N-arylglycosylamines of tri-, tetra-, and penta-saccharides that acetates of N-arylglycosylamines are the most convenient derivatives for the analysis of the structure of higher oligosaccharides by the mass spectrometric method.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1246–1253, June, 1973.