Ethers are not easily differentiated by their infrared spectra,
but they tend to form predictable fragments in
the mass spectrum. The following compounds give similar
but distinctive mass spectra.
Both compounds give prominent peaks at m/z 116, 73, 57,
and 43. But one compound gives a distinctive strong
peak at 87, and the other compound gives a strong peak
at 101. Determine which compound gives the peak at 87
and which one gives the peak at 101. Propose fragmentations
to account for the ions at m/z 116, 101, 87, and 73.