208 CHEMISTRY 



CN 



^ C], a spontaneous polymerization to the di- or tri-molecular 

 COOR 



X XX C/' 



systems, ,C=C V or C v 



/ \ / \ 



Y Y Y C 



X 

 \ 



took place. 



\ 

 Y 



One further point with reference to unsaturated compounds must 

 now be presented. 



Intramolecular Rearrangements shown by Unsaturated Systems 



From the discussion presented above it is obvious that trimethyl- 

 ene and propyleneoxide, belonging to class 3, must contain a small 

 percentage of active particles; the dissociation of the triatomic ring 

 in the former case can lead to only one form of active molecule, namely, 

 CH 2 CH 2 CH 2 ; whereas propyleneoxide may give the follow- 

 ing three active molecules: 

 0- 



I 

 CH S -CH-CH 2 - (A); 



I I 



CH 3 CH-CH 2 -O (B); 



I I 



and CH S CH-0-CH 2 (C). 



Since propyleneoxide absorbs dry ammonia or hydrogen chloride, 

 as was proved by especially careful and exhaustive experiments, giv- 

 ing addition products of the general formula 



CH 3 CHOH-CH 2 X [X = C1 or NH 2 ], 



the only possible conclusion that can be reached is that propylene- 

 oxide contains relatively more active A than active B or C mole- 

 cules; consequently the absorption reactions proceed by preference 

 in only one of three theoretically possible directions. 



When trimethylene or propyleneoxide is heated or placed in con- 

 tact with various catalytic agents, the percent of active particles must 

 naturally increase, and when a definite limit has been reached a spon- 

 taneous transformation of trimethylene into propylene and of propy- 

 leneoxide into propylaldehyde (f) and acetone () takes place; both 

 reactions are non-reversible. These results can only be explained in 

 the following manner: aside from the increase in active particles 



