METHOD OF PREPARING ALLOBETULIN Russian patent published in 2001 - IPC

FIELD: chemical industry. SUBSTANCE: described is synthesis of allobetulin (19β, 28-epoxy-oleanane-3β-ol) by isomerization of betulinol(lup-20(29)-ene-3β, 28-diol) in the presence of catalysts. Catalyst is orthophosphoric acid, and process is carried out by heating or in solution of oxygencontaining solvents with which acid forms homogeneous solution (homogeneous catalysis), or in solution of hydrocarbons with acid (heterogeneous catalysis) applied onto inert carrier. Weight fraction of allobelutin in isomerization product varies from 81 to 95%. In order to prepare purer allobetulin, isomerization product is recrystallized from ethanol, isopropanol, butanol, and ethyl acetate. Method makes it possible to increase yield of desired product, simplify regeneration of solvents and use equipment made of ordinary alloyed steels. EFFECT: more efficient preparation method. 3 cl, 1 tbl