194 Biological Chemistry. 



Lcevulose or fructose, the other sugar produced by 

 inversion of cane-sugar, is similar in general reactions to 

 dextrose. It is, as already mentioned, laevo-rotatory instead 

 of dextro-rotatory. It also contains five hydroxyl groups, 

 and it also yields with hydrogen cyanide a hydroxy nitrile. 

 The hydroxy nitrile on hydrolysis also yields a hexahydroxy 

 acid ; but this latter on reduction with hydriodic acid gives 

 rise, not to normal heptylic acid, as is the case with the 

 corresponding compound from dextrose, but to methyl butyl 

 acetic acid (which can be synthesized from ethyl malonate 

 through the sodium derivative, see p. 109). Lsevulose was, 

 therefore, held to be a ketone with five hydroxyl groups, 

 and the formula assigned to it was the following : 

 CH 2 -OH 



CH-OH 



I 

 CH-OH 



CH-OH 



CH 2 OH 



or methyl-butyl acetic acid. 



