Answer:
Explanation:
The main assignment here is to provide the structure of A. But before that, let us explain briefly some certain things:
The proton NMR (1H) gives data about the quantity of non-identical protons present in the structure. The resonance frequency is seen regarding the standard compound (0 ppm), which is addressed as a chemical shift. The same protons have equal value of chemical shift.
The protons that are available in a similar environment are addressed as comparable protons and the protons with various conditions are called non-identical protons.
However, from the image below, we can see the reaction of the compound 1,3,5,7-cyclooctatetraene resulting in 2 equivalents of potassium forming an aromatic dianion.