Synthesis of triterpene glycosides
Summary1. The acyl-β-D-glucopyranosides, acyl-β-D-xylopyranosides, and acyl-α-L-arabinopyranosides of oleanolic and ursolic acids have been synthesized for the first time.2. A method for the synthesis of acyl glycosides of triterpene hydroxyacids with hindered carboxy groups has been developed.
Hétérosides stéroïdes et triterpéniques. 2e communication. β-D-Quinovoside de l'acide oléanolique
Nous avons prepare, par la methode de Koenigs & Knorr modifiee par Miescher & Meystre, le β-D-quinovoside de l'acide oleanolique. La protection passagere du groupe carboxyle de l'acide oleanolique fut realisee, pour la synthese glucosidique, par esterification au diphenyldiazomethane. Le groupe carboxyle fut regenere apres cette synthese par hydrogenolyse catalytique au charbon palladie. Le β-D-quinovoside de l'acide oleanolique et tous les derives ont ete obtenus sous forme cristalline; ils sont mentionnes pour la premiere fois dans ce memoire. Le β-D-quinovoside de l'acide oleanolique est le premier saponoside triterpenique artificiel prepare par voie de synthese partielle.
Thermodynamics on the Carbochlorination of Titanium-bearing Ores
The equilibrium compositions of the multi-component, multi-phase and multi-reaction system of carbochlorination of titanium-bearing ores are calculated with HSC, a computational chemistry software. The thermodynamic equilibrium calculation of the reaction system shows that a complete conversion of titanium-bearing ores is feasible at a temperature near 200oC. At temperatures ranging from 800 to 1600oC, the products of the reaction system are all in gaseous phase. Thermodynamic analysis accords with the industrial practice. The simulated results provide reasonable scientific basis for improving suitable technological conditions of the carbochlorination reduction.