[shorty35424]

Can someone please explain why treating 5-hydroxyhexanoic acid with a strong base (such as -OH) does NOT produce a lactone (cyclic ester)? I understand why acidic conditions favor the lactone, but why not the basic. Thanks.

[dipesh747]

First thing I have to say

strong base (such as -OH)

You have defined what a base is, not the strength. Regardless, look into acid/base aldol intramolecular reaction mechanisms and you will get your answer.

[Nosterius]

Hi Dipesh747

If you treat 5-hydroxyhexanoic acid with a base, what would be deprotonated in the first place? Will this deprotonation favor the formation of the desired lactone?

[orgopete]

Given the entropy factor for an intramolecular reaction, I think that is a good question. I further think that if you were to draw out the steps, you would find it unlikely to occur and secondly, if it did, it would be unstable. What would happen if you treat an ester or lactone with a strong base such as hydroxide?

Hint: Beginning with acetic acid, how would you make sodium acetate?