200 



G. DANGSCHAT, H. O. L. FISCHER 



VOL. 4 (1950) 



This shows conchisively that quinic acid bears the same steric relationship to 

 D-glucose as that which has already been demonstrated for shikimic acid^^. 



Furthermore, since the structural connection between quinic acid, IV, -» shikimic 

 acid, V, -> gallic acid, VI, is obvious, it seems to us that in this chemical relationship 

 we have an indication that many hydroaromatic and aromatic plant products aie 

 actually formed biologically from carbohydrates. In addition, it might be mentioned 

 that our transformation in vitro of quinic acid to citric acid, VII, by means of periodic 

 acid^2 has perhaps its biological counterpart in the work of But^ewitsch" who suc- 

 ceeded in establishing a connection between the fermentability of quinic acid and the 

 formation of citric acid in the hfe of bacteria and fungi. 



H H 



H H 



H H 



-CN 



NaOH 



CH, 



COOH 



H H 



Formal shikimic Acid 

 III 



H 



HO 



H H 

 'OH H^ 



XOH H X 



H H 



Quinic Acid 

 IV 



H H 



COOH 



OH 



H /OH 



HO X oH H> 

 H H 



Shikimic Acid 

 V 



HO 



H 



-COOH 



HO- 



ho: 



HO-C-COOH 



C-COOH 



HOOC-HjC CH2-COOH 



Citric Acid 



VII 



HOOC-HC CH2-COOH 



Aconitic Acid 



VIII 



COOH 



H 

 Gallic Acid 



vi 



COOH 

 H-C-H 

 HO-C-H 

 H-C-OH 

 H-C-OH 

 CH2OH 

 2-Desoxygluconic Acid 

 IX 



SUPPLEMENT 



Our experiments described in this paper on the transformation of quinic acid into 

 shikimic acid by splitting out water clearly show how strongly the carboxyl of the 

 quinic acid influences its tertiary hydroxyl in the a position, and probably also the 

 remainder of the molecule. 



References p. 203I204. 



