00:01
Hello students, in this question we have to tell about a reaction which happens between salicyaldehyde.
00:06
Now salicyaldehyde is ortho hydroxy benzaldehyde.
00:14
Now this is reacting with diethyl malonate.
00:18
So it is basically a malonate that contains two ethyl groups at the ester oxygen atoms.
00:29
Now this hydrogen atom is very acidic.
00:32
This type of condensation can happen in acidic conditions as well as in basic condition.
00:38
In basic conditions this hydroxyl group will abstract this hydrogen atom hence generating a very strong nucleophile here.
00:47
Hence the rate of reaction will be increased and in acidic hydrolysis this oxygen atom attacks on the acid hence this bond is broken and a carbocation is generated.
00:59
Hence this side become highly electrophilic.
01:02
That's how acidic and basic mechanism works in this claisen condensation reaction.
01:07
Now if piperidine is used, piperidine is basically basic in nature hence this will abstract this hydrogen and make this more nucleophilic but presence of glacial acetic acid will protonate this carbonyl group hence making it more electrophilic.
01:34
So this will be of acidic nature.
01:37
Now glacial acetic acid not only promote this reaction but also prevents hydration.
01:51
Hence the acid helps in removal of moisture.
01:59
If the reaction contains moisturous conditions in presence of water our ethyl malonate that is cooet, cooet.
02:15
This will be hydrolyzed to the respective acids because ester undergo hydrolysis to give acid and alcohol.
02:26
So two moles of ethanol will be also formed.
02:29
That is why the presence of moisture will degrade our diethyl malonate that is why addition of acid will be preferred.
02:37
Now we have to draw the mechanism for acidic condensation of both these reactants...