Synthesis Of Cordycepin From Adenosine

As the first nucleoside antibiotic separated from epiphyte ,Cordycepin,whose chemical name is 3'-deoxyadenosine, has many pharmacological activities and very high price in international market.On the basis of other shoolars'papers about synthesis route of cordycepin which is mainly studied in this paper,various kinds of technic routes were valued and one optimized route is proposed which includes three parts,such as cyclizing the adenosine,opening the ring used acetyl bromide and deoxidized reaction,in line with the principle of available raw material,low toxicity,simple application,high yield.Then,this route was confirmed experimentally in the lab,and finally the discussion of improvement on the technic condition of the cordycepin synthesis was carried out, in order to improve the industrial value of this route.In first step the adenosine was cyclized,namely,the synthesis of 2',3'-O-Methoxy ethylideneadenosine or 2',3'-O-Methoxymethyleneadenosine by the reaction of adenosine and trimethyl orthoacetate in organic solvent at acid condition.We found better reaction condition through single factor optimizing.Reaction yield is up to 82%,the obtained purity of product is about 99%.We ensure that the product is our target by mass spectrum and ~1H-NMR detecting. Compared with other papers,the technics in this paper is much more simple ,which obviously leads to the reduction of cost.In second step acetyl bromide was used to open the ring,that is the synthesis of 2:(3'),5'-Di-O-acetyl-3'(2')-bromoadenosine,which is obtained by the reaction of acetyl bromide and 2',3'-O-Methoxyethylideneadenosine in suitable organic solvent. We found better reaction condition through single factor optimizing. Reaction yield is up to 79%,the obtained purity of product is 88%.We ensure that the product is our target by mass spectrum and ~1H-NMR detecting. Compared with yield of 60% in other paper,that in this paper is higher.In third step deoxidized reaction was carried out,that is the synthesis of cordycepin, which is obtained through catalytic hydrogenation of 2'(3'),5'-Di-O- acetyl-3'(2')- bromoadenosine, Pd/C is the catalyzer,then hydrolyzed in alkaline solvent. Reaction yield is up to 4%,the obtained purity of product is 21%. We ensure that the product is our target by HPLC detecting.In this technic route, adenosine as raw material is chcaf and very easy to obtain,it hasgood applied foreground.The work in this paper is helpful to synthesis of cordycepin.It has no resemble report in home yet.