6 OPTICAL ACTIVATIOX 



prepared by catalysis, if }X)ssible, the oDtically active isomeric 

 Viromcanipliors and liromcamphor-carboxylie acids, from the 

 racemic bromcampbur-carboxylic acid. This acid is found to 

 be much better suited for catalytic asymmetric division than 

 campbor-carboxylic acid, for which the former ixid the quantity 

 of catalj'st, calculated in equivalents, can be very much smellier 

 than that of the decomposed sultstrate. 

 Peepaeatioxs. 



Inactive solvent : Acetophenone was obtained from C. F. 

 Kahlbaum, and before being used it was dried over anhydrous 

 sodium sulphate and redistilled. 



Acids : d-. 1-. and in-bromcam]:)hor-carl:)Oxylic acids. 

 These acids were prej)ared from the corresponding camphor- 

 carboxylic acids. As difficulties had been experienced in 

 obtaining perfectly pure bromcamphor-carboxylic acids, it was 

 thought best to start with absolutely pure camphor-carboxylic 

 acids. These were i^repared according to the sodium amide-^ 

 method of BruhJ~. The inactive acid was prepared from 

 synthetic camphor, (very kindly presented hy the chemischen 

 Fabrik auf Aktien vorm. E. Schering, Berlin), after its slight 

 dextro rotation had been compensated by the addition of the 

 requisite amount of 1- camphor. The best yields of camphor 

 carlx)xylie acid were obtained when the sodium amide was 

 finely divided, the temjDerature high (110" — 140^), and the 

 stirring as rapid as possible. , It was found that the sodium 

 amide could be conveniently ground up in an ordinary mortar 

 under toluene. By using toluene or xylene for the reaction 

 liquid, a favourable temperature was obtained. In order to 

 stir the mixture rapidly, and also to lessen the chance of 

 breakage, owing .to the tendency of the sodium amide to adhere 

 to the sides of the glass flask, the use of an iron vessel was tried. 

 It was found, howover, that the amide acted on the iron to a 

 certain extent, a substance resembling Prussian Blue being 

 formed, and that it required several crystallisations to obtain 



1. For the fresh sodium amide I am indebted to the Deutschen Gold- 

 und Silberscheideanstalt. Frankfort a/M 



2. Bruhl. J. W.: Ber. d. deutsch. cheni. Ges., 36, 1305, a903). 



