The following spectra for A and B correspond to two structural isomers. The NMR singlet...

The following spectra for A and B correspond to two structural isomers. The NMR singlet at δ 1.16 in spectrum A disappears when the sample is shaken with The singlet at δ0.6 ppm in the spectrum of B disappears on shaking with D₂O. Propose structures for these isomers, and show how your structures correspond to the spectra. Show what cleavage is responsible for the base peak at m/z 44 in the mass spectrum of A and the prominent peak at m/z 58 in the mass spectrum of B.