146 



J. BADDILEY 



■0 



OH OH 

 I I 

 •-CHCH-CHCH-CH.OTri 



I 



' T 



5'-Trityladenosine 



TsO OTs 

 I I 

 CHCH-CH-CH-CH^G 



^ U> 



TsHN ^ 



;V6,2',3'-Tritosyl-5'-trityladenosin 



-0- 



TriHN ^^ 



OH OH 



•-CHCH-CH-CH-CHj OTri 



(1) AciO 



(2) HAc 



N N 

 NH. ^^ 



AcO OAc 

 I I 

 CH-CH-CH-CH-CHj-Ol 



iV^,5'-Ditrityladenosine 



2',3'-Diacetyladenosine 



The structure of 2',3'-diacetyladenosine is confirmed by reaction with 

 p-toluenesulfonyl chloride, giving the A^^,5'-ditosyl derivative. Only one 

 tosyloxy group in this compound may be replaced by iodine on treatment 

 with sodium iodide.*^ 



Similar transformations have established the furanose structure for uri- 

 dine. Uridine forms mono- and ditrityl derivatives."'^^" Methylation, 

 then hydrolysis, of monotrityluridine gives 2',3'-dimethyluridine. The lat- 

 ter substance forms a monotosyl derivative which reacts readily with so- 

 dium iodide to give crystalline 5'-iodo-2',3'-dimethyluridine. It follows 

 that the original trityl compound is 5'-trityluridine. Also, tosylation of this 

 compound gives 2',3'-ditosyl-5'-trityluridine, which after hydrolysis of the 

 trityl residue does not react with sodium iodide. 



Tritylcytidine^^ • ^^ and tritylguanosine^^ are probably 5'-trityl deriva- 

 tives. In view of the insolubility of guanosine in pyridine the trityl deriva- 

 tive must be prepared by an indirect method. 



Thymidine forms a monotrityl derivative.''" This is believed to be 5'-tri- 

 tylthymidine since it may be converted into a monotosyl compound (3'- 

 tosyl-5'-tritylthymidine) which does not react with sodium iodide. It fol- 

 lows that thymidine possesses a furanose ring. 



Further support for the furanose configuration of thymidine is obtained 

 from the observation that, unlike guanosine and inosine, it does not increase 



" P. A. Levene and R. S. Tipson, J. Biol. Chem. 105, 419 (1934). 

 38 H. Bredereck, E. Berger, and J. Ehrenberg, Ber. 73, 269 (1940). 

 " H. Bredereck and E. Berger, Ber. 73, 1124 (1940). 

 ^» P. A. Levene and R. S. Tipson, J. Biol. Chem. 109, 623 (1935). 



