219 



8. Pasteur's first fission of a racemoid according to the 

 method described, was the fission of the racemic acid itself into 

 the tartaric acids by the aid of the dextrogyratory base cinchonine J ). 

 Later he did this by means of quinidine and cinchonicine , which 

 bases are also both dextrogyratory. From the solution, the cincho- 

 nicine-l-tartrate crystallises first, being less soluble than the corres- 

 ponding d-tartrate. If quinidine be used, the d-tartrate crystallises first. 

 Since that time numerous fissions of racemic acids by means of 

 optically active bases have been made: the bases used were chiefly 

 natural alkaloids, as: strychnine, brucine, morphine, quinine, cincho- 

 nine, cinchonicine' 2 '), etc., and more recently bases such as: ot-phenyl- 

 ethyl-amine 3 ) , hydroxy-hydrindamine 4 ), etc. On the other hand, 

 many racemic bases are resolved by means of optically active 

 acids: d-tartaric acid, l-malic acid, and since 1898, when Pope 

 and Peachy 5 ) introduced some strongly optically active camphor- 

 derivatives for that purpose, especially by means of the camphor- 

 sulphonic, and the chloro-, resp. bromo-camphor-sulphonic acids. 



Thus lactic acid'. CH 3 CH(OH)COOH, was separated by Jung- 

 fleisch 6 ) by means of quinidine, and by Purdie and Walker 7 ) 

 by means of strychnine. 



Loven 8 ) separated a-phenyl-ethyl-amine by means of l-malic 

 acid, while Pope and Read 9 ) made this fission by condensation 

 with d-oxymethylene-camphor . Ladenburg 10 ) in his famous syn- 

 thesis of coniine, was able to separate the obtained inactive base 

 into its optically active components by means of d-tartaric acid, 

 while Pope and Read 11 ) resolved hydroxy-hydrindamine by means 



!) L. Pasteur, Compt. rend., 36, 191, (1852); Ann. de Chim. et Phys., (3), 

 8, 437, (1853). 



2 ) L. Pasteur, Jahresber. f. Chern., (1860), p. 250. 



3 ) W. J, Pope and J. Read, Journ. Chem. Soc. London, 95, 172, (1909); 103, 

 51, (1913); J. M. Loven, Ber. d. d. Chem. Ges. 29, 2313, (1896); W. Marck- 

 wald and R. Meth, ibid., 38, 801, (1905). 



4 ) W. J. Pope and J. Read, Journ. Chem. Soc., 99, 2071, (1911); 101, 758, 

 (1912); 103, 447, (1913). 



5) W. J. Pope and S. J. Peachy, Journ. Chem. Soc., 73, 893, (1898); F. S. 

 Kipping and W. J. Pope, ibid., 63, 548, (1893). 



6) E. Jungfleisch, Compt. rend., 139, 56, (1904). 



7) T. Purdie and J. W. Walker, Journ. Chem. Soc. London, 61,754, (1892). 



8) J. M. Loven, Journ. f. prakt. Chemie, (2), 72, 307, (1905). 



9) W. J. Pope and J. Read, Journ. Chem. Soc., 103, 451, (1913). 

 *<>) A. Ladenburg, Ann. der Chemie, 247, 85, (1886). 



u ) W. J. Pope and J. Read, Journ. Chem. Soc. London, 101, 758, (1912). 



