48 W. G. OVEREND AND M. STACEY 



ment of the 1-diazo-l-deoxy-fce/o-D-psicose tetra-0-acetate so formed, with 

 copper acetate and acetic acid.^^* 



Soon after the first preparation of D-ribose, Fischer^^* succeeded in re- 

 ducing ribonolactone through the free sugar to a polyol (ribitol, adonitol). 

 Catalytic reduction with Raney nickel of aldehydo-D-rihose 2,3,4,5-tetra- 

 0-acetate afforded 2,3,4,5-tetra-0-acetylribitol.2" A method has been 

 patented for the hydrogenation of sugars to the corresponding polyol by 

 magnesium-activated Raney nickel and in this way ribose can be converted 

 to ribitol practically quantitatively."^ 



The condensation of nitromethane with D-ribose has been studied by 

 Sowden and Fischer,^ • ^^^ and the results have been discussed in a recent 

 extensive review.^^" Like other pentoses D-ribose is converted to furfural 

 when heated with dilute acid: quantitative aspects of the conversion have 

 been investigated.^*' The behavior of ribose in the Kiliani-Fischer synthesis 

 has been reviewed by Hudson^*^ (see also Richtmyer^^. 



rv. Chemistry of 2-Deoxyribose 



1. Preparation 



The isolation of 2-deoxy-D-ribose from deoxyribonucleic acid has proved 

 to be very difficult. In early experiments it was usual to degrade the nucleic 

 acid by chemical methods to the constituent nucleosides, separate these, 

 and then hydrolyze the glycosidic linkage and isolate the sugar portion. 

 Separation of the nucleosides w^as a tedious procedure, and, since acidic 

 treatment for hydrolysis results irl the conversion of some of the deoxy- 

 pentose to levulinic acid, yields were poor. Following attempts by Thann- 

 hauser and Ottenstein,^®^ who employed picric acid for the hydrolysis of 

 thymus nucleic acid and obtained diphosphoric esters of pyrimidine deoxy- 

 ribosides, Levene and London^^ resorted to enzymic methods of degrada- 

 tion and isolated deoxyribonucleosides of guanine, hypoxanthine (arising 

 from deamination of adenine), cytosine and thjrmine. Very mild hydrolysis 

 of the guanine nucleoside gave the deoxysugar in crystalline form.^**- ^^^ 



2" M. L. Wolfrom, A. Thompson, and E. F. Evans, /. A7n. Chetn. Soc. 67, 1793 (1945). 



266 E. Fischer, Ber. 26, 633 (1893). 



2" H. H. Fox, /. Org. Chem. 13, 580 (1948). 



"8 L. A. Flexser, U. S. Pat. 2,421,416 (June 3, 1947). 



"9 J. C. Sowden and H. O. L. Fischer, U. S. Pat. 2,480,785 (Aug. 30, 1949). 



26' J. C. Sowden, Advances in Carbohydrate Chem. 6, 291 (1951). 



261 R. C. Hockett, A. Guttag, and M. E. Smith, J. Am. Chem. Soc. 66, 1 (1943). 



262 C. S. Hudson, Advances in Carbohydrate Chem. 1, 1 (1945). 



263 S. J. Thannhauser and B. Ottenstein, Z. physiol. Chem. 114, 17, 39 (1921). 



264 p. A. Levene and E. S. London, /. Biol. Chem. 83, 793 (1929). 

 266 P. A. Levene and T. Mori, /. Biol. Chem. 83, 803 (1929). 



266 p. A. Levene, L. A. Mikeska, and T. Mori, /. Biol. Chem. 86, 785 (1930). 



