150 



J. BADDILEY 



and 2,6,8-trichloropurine and were prepared from the silver salts of the 

 appropriate purines and acetohalogeno-sugars. The products were deacetyl- 

 ated with ammonia in methanol.^" Theophylline and theobromine hexo- 

 sides,^"' ^1 pentosides,^!-^^ methyl pentosides,^^-^^ a glucodesoside,*» and a 

 rhamnofuranoside®" may be prepared in this way. A comparison of the 

 absorption spectra of these substances with known derivatives of theophyl- 

 line and theobromine indicates that the theophylline derivatives are 7-gly- 

 cosides and the theobromine derivatives are O-glycosides.^^ However, the 

 silver salts of 2,6,8-trichloropurine and 2 , 8-dichloroadenine also react 

 with acetohalogenosugars^o giving acetylated glycosides. The 2, 8-dichloro- 

 adenine glucoside is a 9-glucopyranoside as is shown by its absorption spec- 

 trum^" and by periodate oxidation. The deacetylated glucoside may be 

 converted into 9-D-glucopyranosyl-adenine or -guanine by appropriate 

 substitution of the chlorine atoms as shown. 



In order to apply this method of synthesis to the natural purine nucleo- 

 sides an acetohalogenoribofuranose is required. The bromo compound is 

 prepared from 5-trityl-D-ribose, through 5-trityl-l ,2,3-triacetylribose, from 



60 E. Fischer and B. Helferich, Ber. 47, 210 (1914) . 



" B. Helferich and M. von Kuhlewein, Ber. 53, 17 (1920). 



52 E. Fischer, Ber. 47, 1377 (1914). 



" J. Pryde and R. T. Williams, /. Chem. Soc. 1933, 640. 



" G. A. Howard, B. Lythgoe, and A. R. Todd, J. Chem. Soc. 1947, 1052. 



66 P. A. Levene and H. Sobotka, J. Biol. Chem. 65, 463 (1925). 



" E. Fischer, B. Helferich, and P. Ostmann, Ber. 53, 873 (1920). 



" E. Fischer and K. von Fodor, Ber. 47, 1058 (1914). 



6» P. A. Levene and J. Compton, /. Biol. Chem. 117, 37 (1937). 



" P. A. Levene and F. Cortese, /. Biol. Chem. 92, 53 (1931). 



80 P. A. Levene and J. Compton, J. Biol. Chem. 114, 9 (1936). 



