If you want to solve this
problem, you have to clarify two basic questions:
- Would you expect to detect coupling between HA and HM, or between HA and HX? Oh yes, you would!
In both cases coupling should occur, since HA and HM, as well as HX are not
equivalent, and they are separated by only three
bonds.
We would also expect JAM to
be larger than JAX, since in
the former case the coupling is mediated through a p bond.
- Are HM
and the HX
equivalent to each other?
Of course, they aren't! They are in very different chemical
environments.
We can therefore rephrase the problem as follows:
What is the effect of the coupling between the
non-equivalent protons HM,
HX
and HA
in
on the signal of HA?
You think you know the answer? Compare it to ours in the box on page 89!
Otherwise move on to page page 95
|
|