00:01
Hello students, this question consists of multiple part.
00:04
In the first part we are going to prepare ethyl 2 -methyl -3 -oxopentanoate from ethyl propanoate.
00:11
This is the ethyl propanoate.
00:13
This ethyl propanoate will undergo glycine condensation.
00:16
The first step is the proton abstraction.
00:19
The proton is abstracted by the ethoxide ion and this has been eliminated as ethanol and this result in the formation of a negative charge over here.
00:30
This negative charge will attack the carbonyl carbon of another molecule of ethyl propanoate.
00:34
Therefore, this bond will shits over here and this result in the formation of a negative charge over the oxygen that can be written as follows ch2o, c double bond o and this has been attached to a ch and a methyl group and this has been attached to o and ch2, ch3 and here will be the negative charged oxygen and here will be our ethyl group.
01:00
Now, this negative charge will comes over here and this ethoxide ion will be eliminated and this result in the formation of our expected product that is ethyl group, oxygen and a carbonyl group and another carbonyl group and here will be a methyl group and here will be the ethyl substituent.
01:24
So, this is the answer to the first question.
01:26
Coming to the second question, michael reaction of ethyl acetoacetate with buta -3 -ene -2 -one.
01:33
Michael reaction is nothing but the michael addition.
01:36
In the first step, the hydrogen has been abstracted by the hydroxide ion.
01:42
So, this result in the formation of a negative charge over here.
01:45
This negative charge will attack this carbonyl carbon and this will shits over here and this will shits over here and result in the formation of our intermediate with a negative charge over the oxygen and double bond o.
02:01
This has been attached to double bond o and here will be the second compound and here will be our oxygen group with o-.
02:12
This o - will abstract the hydrogen from the water molecule and thus hydroxide ion will be eliminated and thus result in the formation of a enol compound.
02:25
So, c double bond och double bond bond oh.
02:32
This hydrogen will be eliminated and this bond shits over here and this bond which shits over here and the eliminated hydrogen will attack over here...