In the base catalysed hydrolysis the hydroxide ion adds to the ester to form a tetrahedral intermediate, after which the alkoxide ions leave and forms carboxylate ion and alcohol.
Also we find the rate of reaction to be quite high.
So my questions are:
- Most importantly, alkoxide is a very strong base. So why is it acting as a leaving group here (apparently, a very good leaving group due to the high rate of reaction)?
- Why is the tertrahedral intermediate not as stable as the corresponding ones of carbonyl compounds?
- Why is this reaction essentially irreversible, considering the fact that alkoxide is a stronger base the hydroxide ion? (Therefore it should be able to displace the hydroxide in the hypothetical backward reaction.)