Tiglath M. answered 02/11/16
UC Berkeley Grad for Chemistry, Organic Chemistry and Biology Tutoring
I'm assuming that that you're asking whether acidic or basic conditions are required to prepare ethyl ethanoate from acetic acid.
Under acidic conditions
C4H8O2 + H3O+ -> C4H9O2+ + H2O
Under basic conditions
C4H8O2 + OH- ->C4H8O2-
One thing to note about the second reaction is that the intermediate shown does not last long as the carbonyl group is reformed and an alkoxide group is expelled. The resulting product is then deprotonated by the alkoxide ion to form a carboxylate ion.
You should notice from the explanation about the second reaction that the first route is the preferred method to prepare ethyl ethanoate. This method is called the Fisher Esterifaction process that can be used to prepare esters from carboxylic acids and alcohols. The second route called saponification which uses a base followed by an acid is the reverse of the Fisher Esterfication process can be used to convert esters to carboxylic acids.
Hopefully this answers your question.