634 REPORT— 1903. 



The hydrolysis of this compound gave a colourless liquid (b.p. 153°-156° 

 under 13 mm. pressure), which readily reduced Fehling's solution and showed in 

 approximately 5 per cent, alcoholic solution a specific rotation of — 217°. The 

 substance was evidently comparatively pure tetramethyl fructose. No crystalline 

 derivative of the compound being obtained, we have thus so far no direct evidence 

 of its production in the hydrolysis of alkylated cane-sugar. 



The production from cane-sugar of the identical tetramethyl glucose previously 

 obtained from methyl glucoside shows that the linking of the glucose residue in 

 the former is the same as in the latter compound, and consequently Fischer's 

 formula,' 



, , 



CH^OH • CIIOH • CH • (CHOH)^ • CH 



O 



I 

 CH.OH • CH • (CITOH),, • C • CHpII 



' 1 o^^l 



so far as the glucose half of the molecule is concerned, is proved to be correct. 



Alkylation of Maltose. 



The method adopted was similar to that already described for cane-sugar, save 

 that no solvent water was required. The process was at first attended with an 

 appreciable amount of oxidation, and after the first treatment the syrup obtained 

 was acid in reaction. The final product was a thick neutral sj"rup without action 

 on Fehling until hydrolysed. The assumption is that the free aldehyde group had 

 been oxidised, and subsequently methylated. The substance was hydrolysed by 

 boiling for an hour with 1^ per cent, hydrochloric acid. The solution was neutra- 

 lised exactly with barium hydrate, evaporated in a vacuum at 60°, and the residue 

 extracted with boiling alcohol. A mixture of the methylated glucose with the 

 barium salt of the oxidation acid was thus obtained, from which the alkylated 

 sugar was extracted with ether. From this extract tetramethyl glucose was ob- 

 tained on distillation in a vacuum, and the substance, after removal of a trace of 

 organic acid and some incompletely alkylated glucose, was finally obtained crystal- 

 line. After recrystallisation from ligroin the compound melted sharply at 84°, and 

 its identity was further confirmed by analysis. 



The acid produced by the oxidation was recovered from the barium salt. It 

 distilled in a vacuum apparently without decomposition, and the figures obtained 

 from combustions and methoxyl determinations agreed approximately with those 

 required for tetramethyl gluconic acid. 



The above results show that the linkage of the glucose residues in maltose is 

 not of the acetal, but of the glucosidic type, and are in agreement with the 

 formula 



CHO • (CHOH), • CH,-0-CH • (CPIOHY, • CII • CHOH • CH.OH 



' I 0—1-1 



suggested by Fischer.* 



The alkylation of polysaccharides and glucosldes, and the identification of the 

 alkylated products obtained by hydrolysis, seem to furnish a general method for 

 elucidating the constitution of these compounds, and the authors are continuing 

 their experiments in this direction. 



' Ber. (1893), 26, 2405. » Loc. cit. 



