658 
• The Philippine Journal of Science 
1921 
When the reaction is catalyzed by — H — , the acetic acid 
is directly attacked, forming: 
0 cc H + 
II 
h 3 c — c 
1 • 
0 
H 
in which the electrons of the double bond are drawn forcibly 
away from the carbon atom. It is therefore a very reasonable 
assumption that a large number of these catalyzed molecules 
take the half-dissociated form: 
H 
0 
h 3 c — c + ^ 
0 
H 
It is to be noted that the carbon atom becomes very unsatu- 
rated, having now two vacancies in its shell. It therefore is 
very reactive, and an addition product with alcohol is formed: 
H 
0 
Compound A | + 
H 3 C - C D 0 - C 2 H 5 
0 H 
H 
Again the first compound is unstable. The accumulation of 
positive charge near the alcohol oxygen releases the attached 
+ 
hydrogen as — H — giving: 
