Study On The Reaction For Synthesizing Farnesol By Catalytic Isomerization

Famesol,as a kind of flavor compound,mainly exists in plant essential oil．It iswidely used not only in cosmetic and slap—up but also as an inevitable material to make insecticide．We must investigate artificial methods preparation of farnesol because its natural resource does not meet market request． On the basis of consulting an amount of literatures and comparing differentsynthetic methods,a route of isomerization of nerolidol to produce farnesol wasadopted．The route has many advantages such as simple,easily separately,etc．Isomerization of nerolidol and preparation of catalyst isomerization are two committed steps of the method in this paper． It is the first time that farnesol was prepared by nerolidol isomerization in China．On the basis of researching catalyst,the isomerization reaction of　nerolidol wasinvestigated in detail,and then the optimum technical conditions are selected toprepare farnesol in a higher yield．Physical properties and chemical properties oforthovanadates,the key catalysts,and the final product famesol were determined．Thepossible reaction mechanism and chemical structure of farnesol was discussed tOo inthepaper． Several kinds of orthovanadate were prepared through the reactions between ammonium metavanadate and organic alcohols,and then the properties of the orthovanadates were determined． After studying the effect of different kinds of single catalysts such as metavanadates,molybdates and tungstates on conversion of nerolidol to famesol in different temperature,time,catalyst content,and SO on,the propriety reaction conditions were obtained as:ammonium metavanadate as a catalyst．reaction temperature 1 80~C,reaction time 5 h,and catalyst content 0．25％　 The reaction conducted farnesol in a yield of 3 6％in the isomerization product．The effects of some factors such as type of orthovanadate as a single catalyst,temperature,and reaction time,catalyst content on the conversion were studied．Theoptimum conditions are"catalyst triisobutyl orthvanadate,temperature 1 80~C．time 4．5h,catalyst ratio 0．3％,which give famesol in a yield of 37．2％． Some multiplex catalysts prepared from ammonium othovanadate,triisobutylorthovanadate and triphenylsiliconic orthovanadate are originally applied for nerolid01isomerization to fames01．It is found that the CO．effect of the multiplex catalysts is notvery significant,and the results indicated that more kinds of catalytic reactions shouldbe carried out to raise the yield effectively．...