a EED 
Chemistry. — Professor Lory pe BrurN presents, also in the name 
of Mr. W. ALBERDA VAN EKENSTEIN a communication on 
4 Formaldehyd (methylene) derivatives of sugars and glucosides.” 
In a previous communication’) we have already stated that an 
aqueous solution of formaldehyde when evaporated with some of the 
sugars reacts on the same. This was shown by the great changes 
in the rotation. We then also remarked that attempts to isolate the 
crystalline compounds from the syrupy mass had not proved successful. 
These, moreover, are readily dissociated by evaporation in the pre- 
sence of much water, the pure sugars being left behind. ’) 
About the same time *) TorreNs had prepared a crystallised methy- 
leneglucose by mixing a solution of glucose in formaldehyde with 
hydrochloric and acetic acids and setting the liquid aside for some 
months. He obtained a monoformal-derivative which still powerfully 
reduced Fruiine’s liquid. Other sugars gave a negative result. 
On continuing our researches it appeared that substances, of an 
apparently different nature and more stable than those occurring in 
the said syrups, are formed when the dry sugars are melted with 
polymerised formaldehyde (trioxymethylene). The rotatory power 
then appears strongly modified and the reducing power decreased : 
this, however, reaches its normal figure on boiling with dilute acid. 
From this follows that during the reaction of the sugar with the 
formaldehyde, the aldehyde groups disappear. 
We now succeeded in isolating in the case of several sugars 
(and glucosides) crystallised compounds or such having a constant 
boiling point, by introducing the fused mass into sulphuric acid of 
various concentrations or phosphoric acid and then agitating the 
liquid with an organic solvent such as chloroform, which dissolves 
the diformal compounds. In some cases there are formed, simulta- 
neously, monoformal derivatives which are readily soluble in alcohol 
and water, but sparingly soluble in chloroform and so behave in this 
respect quite the reverse from the diformal derivatives. 
Both the di- and the mono-methylenesugars no longer react with 
Frniine’s solution and behave indifferently toward phenylhydrazine ; 
the carbonyl groups have therefore disappeared during the action 
of the formaldehyde. After boiling with dilute acids, the reducing 
power returns. These substances must therefore in the first place 
ty Prog, 1900, 9. 
2) Rurr and Outenporrr, Ber. 32. 3236 (1899), have regenerated some sugars 
from different hydrazines by evaporation with solution of formaldehyde. 
5) Ber 32. 2585 (1900); his experiments had commenced some years previously. 
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