00:01
Hello students in this question we have been given a molecular structure and 1h nmr data.
00:06
We have to assign all the protons corresponding values.
00:10
Now let's start looking at the protons.
00:14
So this methyl group will give a 3 hydrogen singlet.
00:18
Since there is only one singlet given in this entire process we can see that.
00:24
Now let's look at hydrogen number e.
00:27
So it will show coupling with the hydrogen that is present at meta position to this e and it will give a doublet.
00:37
Now the proton d will give a doublet because of coupling with hc and another doublet with he.
00:50
So hd must give a double of doublet.
00:53
That is why there is only one double of doublet signal that will be because of the proton e and this methyl singlet will be at 7 .27 because there is only one singlet so this will be because of the proton a.
01:14
So this is because of proton a and this is because of e.
01:23
Now he is showing a doublet.
01:26
Similarly hc will show a doublet because of coupling with the ortho hydrogen.
01:32
So it will show a doublet.
01:34
However hc will not do coupling with he because para coupling is not observed.
01:42
So hc will only give a doublet.
01:44
So the signal of these two doublets can be because of either of proton c or proton e.
01:52
To determine which one is because of c and which one is because of e we can look at this nitro group.
01:58
So this nitro group will apply a minus m effect which will induce a positive charge on ortho carbons and the para carbon.
02:12
So we can see that there will be a positive charge next to the he.
02:17
So that is why this he will be more deshielded...