00:01
In this question we have to write the mechanism for the given reaction.
00:11
The reaction given is between propine and hbr and the reaction is carried out in the presence of a peroxide, ch3 -o -o -c -h -3 and it leads to the formation of this alkyl bromide.
00:28
So, propine is converted to one bromopropine.
00:37
We have to write the mechanism of this reaction.
00:41
The reaction proceeds via free radical mechanism.
00:49
Let us write down the free radical mechanism.
00:52
In this mechanism, the first step, the step one, is called as the chain initiation or we can say the reaction initiation step.
01:04
The initiation takes place via the formation of a free radical.
01:08
We can write down the formation of free radical which is due to the cleavage, homolytic cleavage of the peroxide given.
01:17
The peroxides are not quite stable.
01:19
They readily undergo homolytic cleavage.
01:22
The o -o bond is cleaved and the electron is shared by each of the oxygen atom.
01:28
The bonded electrons they are divided between the two oxygen atoms as a result it leads to the formation of the two methoxy free radicals this is the methoxy free radical after this the reaction proceeds in various steps of the chain reaction the step two of the chain reaction will be the the methoxy free radicals ch3o free radical it attacks the hbr molecule molecule.
02:02
The oxygen with its single unpaired electron forms a bond with the hydrogen.
02:08
The bond between hydrogen and bromine also undergoes homolytic cleavage leading to the formation of ch3 -o -h along with bromine -free radicals.
02:21
In step 3, that is the next step, the bromine -free radical, the bromine -free radical attacks propine.
02:35
Propine is, we can write it as ch3, ch double bond, ch2.
02:42
When the bromine -free radical attacks it, two possible products can be formed.
02:50
We can say the homolytic cleavage of this pi bond can take place.
02:55
The bromine can either attack the terminal carbon atom leading to the formation of ch3, ch, ch2 and br.
03:06
This has an unpaired electron on the central carbon atom...