12 W. G. OVEREND AND M. STAGEY 



nose, D-xylose and D-lyxose) known at that time: that its benzylphenyl- 

 hydrazone differed from that of arabinose;'^ but the melting point and 

 numerical value (though not the sign) of the specific rotation of its osazone 

 and p-bromophenylosazone were the same as for these derivatives of 

 L-arabinose: that on oxidation it gave D-ribonic acid, enantiomorphous 

 with that previously prepared synthetically by Fischer and Piloty,^'* and 

 that on further oxidation it yielded an inactive trihydroxyglutaric acid. 

 Final complete verification was achieved when Alberda van Eken stein 

 and Blanksma succeeded in synthesizing crystalline L-ribose'^ and later 

 D-ribose.^* The synthetic n-ribose was identical with the crystalline sugar 

 obtained by Levene and Jacobs from the purine nucleosides of yeast nucleic 

 acid. 



Simultaneous hydrolysis and oxidation of cytidine with hydrobromic 

 acid and bromine affords bromouracil and D-ribonic acid.''' Since cytidine 

 is readily transformed into uridine by deamination,'^ it follows that the 

 pyrimidine nucleosides of yeast nucleic acid also have D-ribose as the sugar 

 component. Using benzimidazole derivatives Gulland et al.^^'^^ have re- 

 studied recently the problem of the identification of D-ribose in yeast 

 nucleic acid. In the naturally occurring ribosyl-purines and -pyrimidines 

 the sugar is present in the furanose form and is glycosidically linked in the 

 /3-configuration to position 9' of the purine bases or to position 3' of the 

 pyrimidine bases. (Compare some reviews summarizing the evidence lead- 

 ing to these conclusions.^^' -^) These conclusions, initially based on analytical 

 experiments, have been confirmed by synthesis studies^ • ^^'^^ and to some 

 extent by X-ray investigations. ""^^ In nucleic acids, hydroxyl groups in the 

 D-ribose portion of the molecule are concerned in phosphate ester inter- 

 im O. Ruff and G. Ollendorf, Ber. 32, 3234 (1899). 



1* E. Fischer and O. Piloty, Ber. 24, 4214 (1891). 



i^W. Alberda van Ekenstein and J. J. Blanksma, Chem. Weekblad 6, 373 (1909). 



1* W. Alberda van Ekenstein and J. J. Blanksma, Chem. Weekblad 10, 664 (1913). 



1' P. A. Levene and F. B. La Forge, Ber. 45, 608 (1912). 



18 P. A. Levene and W. A. Jacobs, Ber, 43, 3150 (1910). 



13 G. R. Barker and J. M. Gulland, J. Chem. Soc. 1943, 625. 



20 G. R. Barker, Kathleen R. Cooke, and J. M. Gulland, J. Chem. Soc. 1944, 339. 



" G. R. Barker, Kathleen R. Farrar, and J. M. Gulland, J. Chem. Soc. 1947, 21. 



22 R. S. Tipson, Advances in Carbohydrate Chem. 1, 193 (1945). 



23 D. O. Jordan, Ann. Rev. Biochem. 21, 209 (1952). 



2" A. R. Todd, /. Chem. Soc. 1946, 647; Harvey Lectures, Ser. XX, 1-20, 1951-52. 

 2* J. Baddiley, Roy. Inst. Chem. (London), Lectures, Monographs Repts. No. 3, 1-17 



(1950). 

 26 A. M. Michelson, J. Cellular Comp. Physiol. 38, Suppl. 1, 11 (1951). 

 2'S. Furberg, Nature 164, 22 (1949). 



28 S. Furberg, Acta Cryst. 3, 325 (1950). 



29 S. Furberg, Ada Chem. Scand. 4, 751 (1950). 



