[mjb5676]

Can some one explain to me in detail the electron-pushing mechanism for the synthesis of 3-carbethoxycoumarin? The starting materials are salicylaldehyde, diethyl malonate, piperdine, and glacial acetic acid. they are all mixed in ethanol. I have the mechanism written down already, but I am not sure how to explain it.

[Dan]

To get you started: Enol

Have a go and show your attempt (this is a forum rule).

[mjb5676]

I was thinking this was an aldol condensation reaction that formas an aldol. Then Dehydration then results in double bond formation and an α, β unsaturated compound. I lost internet connection a while ago before I wanted to pt a guess. Darn school.

[Dan]

Sounds good so far. This is known as a Knoevenagel Condensation.

So now you have ester and phenol functional groups and you want to form a lactone.

Hint: A lactone is a type of ester