A schematic of the solution is shown below. The information
from the question is given in **black**. Deductions directly from this
information are given in **red**. Points that provide potential key information
are shown in **green** which leads to the structures which are linked via
the **blue** arrows to show the path required to work them all out. There
are, of course, other possible thought pathways.

The crux to this problem is recognising the reagents and the
implications for the functional groups in the starting materials and products
of each step. Recognising the symmetry of **D** from the spectroscopic
data is also important. Once **D** is determined, **C**, **E**, and
**F** follow directly. **C** then gives **B** which in turn gives
**A**. **E** allows access to **H** and also **B**, **G** is
deduced from **E** and **H** from **D**. Note the how the symmetry
and substitutent effects dictate the nitration reactions of **D** and **E**.

Common errors: (1) not being able to identify **A** as being
a bromide from the MS (2) poor interpretation of the reactions (3) not recognising
the symmetry (4) incorrect nitration of **D** and **E**.