ORIGIN AND MAINTEN. OF OPT. ACTIVITY 37 



actions, no intermediate racemic glucose is formed, but the 

 optically active product is obtained immediately (c/., 

 Tomivasu, 1937). 



The catalytic transmission of the asymmetric state was 

 later considered by Strong (1898) in a well known discus- 

 sion on asymmetry and vitalism. 



Asymmetric syntheses were soon experimentally real- 

 ized in the laboratory. Marckwald (1904) synthesized 

 optically active valerianic acid from structurally inactive 

 methylethylmalonic acid in the presence of active brucine. 

 He defined asymmetric synthesis as a process "in which 

 optically active substances are obtained from symmetric 

 compounds through the intermediary of optically active 

 substances." 



The same year McKenzie also realized some asym- 

 metric syntheses. 



Since these pioneer investigations, the literature on this 

 subject has expanded considerably and the synthesis of 

 optically active compounds from structurally inactive 

 material has been carried out by a number of other chem- 

 ists. These researches have been well reviewed by Mc- 

 Kenzie (1932, 1936) and by Ritchie (1933) to whom we 

 refer the reader. 



But, on the question of the fundamental physical mecha- 

 nism by which the asymmetric state of the catalyst is 

 transmitted to the substance acted upon, there are only 

 some still incompletely shaped theories, for example, the 

 theory of the so-called asymmetric induction (see Ritchie, 

 1933)*. 



To summarize, the authors whose views have been de- 

 scribed in this section admitted, generally, that some opti- 

 cally active, relatively simple compounds appeared once 

 in nature and that, bv asvmmetric syntheses, the asvm- 

 metric state has been transmitted to other compounds 

 more and more complicated in structure. 



2. The Transmission of Asymmetry , from the Thermo- 

 dynamic and Kinetic Point of Vieiv. Recent investiga- 

 tions of the kinetics of asymmetric synthesis have con- 



