CONSTITUTION 169 



CH.OI-I CHOII CHCHOHCIIOHCH.OII + HOC,iH,CH,,OII 

 Glucose Saligenin 



CHi 



= CH2OH CHOH CH CHOH CHOH CH . O . CuH^CHjOH + HoO 

 Salicin 



I I 



CH^OH CHOH CH CHOH CHOH CH . OH + HOCyH^OH 



Glucose Hydroquinone 

 -O . 



I 

 CH.OH CHOH CH CHOH CHOH CH . O . C,;H,OH + H,,0 



Arbutin 



I I I 



CH„OH CHOH CH CHOH CHOH CH . OH + HO— C— H 



Glucose Mandelonitrile 



-0- 



C.H, 



CH..OH CHOH CH . CHOH CHOH CH— O— CH + H„0 



Mandelonitrile glucoside 



Moreover, the constitution of amygdalin itself would ap- 

 pear to be best represented by the formula * : — 



I ° 1 r' 



CH2OH CHOH CH CHOH CHOH CH . O . CH2CHOH CH CHOH CHOH CH . O . CH 



' o 1 i^ 



and, by analogy, phaseolunatin is regarded as the glucose 

 ether of acetone cyanhydrin (see p. 179). 



In some cases the natural glucosides have been actually 

 synthesized ; thus salicin has been obtained by the reduction 

 of the corresponding aldehyde glucoside, helicin : — 



C,jH„Og . O . Ci-H^CHO + 2H = CgHnOg . O . CuH^CH„OH 



the helicin itself having been synthesized from glucose and 

 salicylic aldehyde. 



Identification. 



For the identification of glucosides the character of the 

 cleavage products are relied upon ; these products, with the 



* Auld : "J. Chem. Soc, Lond.," 1908, 93, 1279. 



