CHEMISTRY OF NUCLEOSIDES AND NUCLEOTIDES 



175 



reaction with trifluoroacetic anhydride.'" Both isomers give the same 

 product, and it is beheved that an intermediate mixed anhydride is formed 

 between the phosphate group of the starting nucleotide and a trifluoroacetyl 

 group. The anhydride then effects internal phosphorylation with elimina- 

 tion of the trifluoroacetyl group and production of a cyclic phosphate. A 

 cyclic phosphate of theophylline glucoside has been prepared by direct 

 phosphorylation with phosphoryl chloride in pyridine.-"* Its constitution 

 has not been established. 



PO3H, 



-O- 



OH O 

 I I 

 •-CH-CH-CH-CH-CH.-OH 



NH, ^ 



■0- 



OH 



W/ 

 P 



/\ 

 O 



^CH-CH-CH-CH-CH^-OH 



I 



NH2 



Adenylic acid b 



d. Deoxyribose Nucleotides 



Thymidine-5'-phosphate and the luinatural 3'-phosphate are synthesized 

 from 5'-tritylthymidine.'^^ Direct phosphorylation of the trityl compound 

 with dibenzyl phosphorochloridate followed by treatment with hot acetic 

 acid gives thymidine-3'-benzyl phosphate, from which the benzyl group is 

 removed catalytically. 



■0- 



OH 

 I 

 •-CH-CHrCH-CH-CHrOTri 



N^Me 

 OH 



H0-P0(0CH2Phj 



-o4- 



N. 





 I 

 •-CH-CHj-CH-CH-CHs-OH 



I 



N 



OH 



PO:H, 



-0- 





O 

 I 



l-CH-CH^-CH-CH-CHj-OH 

 I 

 N 



OH 



"8 E. Fischer, Ber. 47, 3193 (1914). 



