TKANSACTIONS OF SECTION B. 627 



first three groups, and by the action of a metallic oxide the one configuration is 

 converted into the second more stable one. 

 Thus NaOH or Na^COj convert 



C5H5C . H into C.HjC . H 



II II 



HO.N N.OM' 



C,H,C . CH, .. C,H,C . CH, 



II II 



HO.N N.OM' 



C,H,.N ., C,H,N 



II II 



HO.N N.OM' 



Application of the Theory to the Acid Amides. — Suppose we reverse the con- 

 figurations 1 and 2, we get a formula which is capable of foi-ming two con- 

 figurations : 



Svn Anti 



K'N K'N 



II II 



HO. OH 



E'N 



II 

 R'.C.OH 



These formul?e will fully account for the constitution of the acid amides. 



Before proceeding to apply the theory, I will assume that the acid amides, 

 which form Ag compound and crystallise in prisms, belong to the ' anti,' and those 

 which do not, belong to the ' syn ' configuration, and crystallise in plates. We can 

 now predict which of the acid amides belong to the former class and which to the 

 latter group. 



1. All the acid amides derived from ammonia or fatty amines must be ' anti ' 

 compounds of the general formula 



H or C„H2a+iN 

 II 

 H or CnHan+i or C^H, . C . OH 



2. Bodies derived from aromatic amines must ha^ve the 'syn' configuration: 



C^H^N 



II 

 HO . C . H or C„H2n+i or C^H^, &c. 



Formanilide forms the only exception. This substance should belong to Group 

 2, but evidently belongs to Group 1. The other modification, which should be 

 easily obtainable, will crystallise in plates, and wiU not form an Ag compound 

 without reversal into the ' anti ' form. 



In anthranil, oxindol, and hydrocarbostyril, we have inner acid amides corre- 

 sponding to the first three anilides. In these compounds it is obvious that the 

 bydro.xyl group must occupy the anti-configuration, and should unite with silver oxide 

 and crystallise in prisms. This is the case, although in anthranil the Ag compound 

 rapidly undergoes reduction : 



C,H,-N C,H, N C.H, N 



Ml I II I II 



C.OH CH, .C.OH CH..CH..C.OH 



Anthranil Oxindol Hydrocarbostyril 



The same principle may be applied to the closed chains in the fatty compounds, 

 which should give stable Ag compounds : 



CH,— N CH„— N 



i ■ II ok/ " 



CHj— C.OH ^ -\ 



CH3-C . OH 



B a 2 



