EN
Fraxin obtaining from industrial end lye has been utilized as initial material to isofraxidin synthesis. Three ways of synthesis of this compound have been studied. Taking into consideration the efficiency and the level of difficulty it has been recognized that the best one is the method of isofraxidin obtainment from fraxin on the way of four steps synthesis consisting in initial hydrolysis of fraxin into fraxetin, specific blocking of fraxetin by phenacyl group in position 7, passing of phenol group in position 8 into methoxyl function and unblocking of hydroxyl group in position 7. This method lets isofraxidin obtainment with the general efficiency 50,2%. It makes possible to use fraxin to synthesis of this deficit hydroxycoumarin.