Glycosylation of betulin acetates with glycals

Betulin 2-deoxy-α-d-, 2-deoxy-α-l-, and 2,6-dideoxy-α-l-arabino-hexopyranosides were synthesized by acid-catalyzed glycosylation (cationite in the H⁺ form, LiBr) of betulin 3- and 28-monoacetates with glycal acetates. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 531–534, March, 1998.     

13C NMR spectra of biologically active compounds. VIII. Stereochemistry of a triterpeneglycoside — Glycyrrhizic acid — And its derivatives

Details of the¹³C NMR spectra of glycyrrhizic acid and four of its derivatives are given, and on their basis the configurations of the anomeric centers of the carbohydrate chain have been redetermined and the β-configuration of the C-1′ carbon atom has been suggested. Institute of Chemistry, Bashkir Scientific Center, Urals Branch, USSR Academy of Sciences, Ufa. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 500–505, July–August, 1989.     

Oxidation of Betulin and Its Monoacetates by “Activated” DMSO

The oxidation of betulin and its 3-O- and 28-O-acetates by activated dimethylsulfoxide was investigated.