Synthesis of Sugars. :381 



-with 5 grains of Sr H2O2, 25 c.c, 4U % CHgO and 500 c.c. water). 



.Soluble Barium and Strontium forniates are produced, and the 

 reducing sugars contain a high proportion of a pentose sugar 

 resembling arabinoketose, and less soluble in 95 % alcohol than the 



-hexoses. 



Magnesium hydratt. — To complete the reaction an excess is 

 required, and either 2 days' heating on a water bath, or 4 to 6 

 hours' boiling. Magnesium formate is produced, and the reducing 

 sugars give an abundant precipitate of golden yellow needles with 

 phenylhydrazin. Most of these resembled the bundles produced 

 with arabinoketose, but a smaller proportion appeared to corre- 

 spond to a glucosazone. 



Ammonium hydrate. — Anmionia directly combines with formal- 



•dehyde to form urotropin. If magnesium powder is added, am- 

 monia slowly escapes, formaldehyde reappears, and magnesium 

 formate is slowly formed, and the residue is black instead of white. 

 After 3 months at 12° C, the filtered liquid blackens with sul- 

 phuric acid, but contains no reducing sugar. The formaldehyde 

 present is, however, partly converted into reducing sugar by pro- 

 longed boiling with Magnesium hydrate.. 



This observation shows that the Magnesium of chlorophyll might 

 be able to liberate formaldehyde from a non-volatile temporary 



.storage combination for subsequent polymerization to sugar. 



Alkaline carhonafes. — If 10 % NagCOg is dripped sloAvly into 

 boiling 5 % CH2O, the reaction lags considerably, and an excess 



• of Na2C03 is always present by the time all the CH2O has disap- 

 peared. This causes the syrup to turn brown. Using 2 grams of 

 Nfto CO3 to 20 c.c. of 40 % CH2O and 200 c.c. of water, the reac- 

 tion was completed after 2 hours' boiling. Using 0.5 graniJi of 

 Na2C03, prolonged boiling was needed to complete the reaction, 



.and a small trace of Na2C03 still remained; less sugar was formed. 

 The addition of absolute alcohol to the syrup precipitates the 



: sodium carbonate remaining, and a second addition of alcohol 

 after concentrating to a small ])u]k precipitates nearly all the 

 sodium formate. A second repetition leaves a solution of a nearly 

 pure mixture of reducing sugars, containing l;oth pentoses and 

 hexoses. 



Potassiiim carbonate acts similarly to sodium carbonate, but is 

 much less active, prolonged boiling l>eing necessary, with an excess 

 of the carbonate. The bi-carbonate is still less active, but the 

 ])ro(lucts aie the same, namely, sodium foriiiMte, methyl alcohol. 



rund reducing sugars. 



