|You would be right if
this molecule would be rigid. In that case one of the signals from the
methyl group should arise from H1,
and the second signal - with twice the intensity - should arise from H2 and H3.
However, the methyl protons in acetealdehyde show at room
temperature only a single, shared signal. That is, the methyl
protons have the same electronic environment and have the same chemical
| Try to come up with an explanation for the
observation and compare your answer with the official solution.
(Hint: Is the shown structure the only possible conformation for