CARBOHYDRATES. 



COH 

 * CH . OH 

 *CH.OH 

 *GH.OH 



17 



*CH.OH 

 CH 9 . 



OH 



According to the rule given above, 2 4 = 16 different compounds should 

 exist having such*a structure. There is really no doubt concerning this, 

 for already no less than twelve isomers representing six optical pairs have 

 been isolated. For each one of these the geometric constitution is ex- 

 plained by the theory, and the configuration of each single molecule 

 represented by a definite structural formula. The following is a summary 

 of the configuration formulae given by Fischer to the hexoses, 1 in which 

 the asymmetric carbon atoms are marked with an asterisk. 



The configuration formulae for sugars with less carbon have also been worked out. 



