Why benzaldehyde ortho hydrogen is more deshielded than para hydrogen?

25 March 2024 0 5K Report

I am doing NMR practice, and the task is to assign the 1H NMR to the correct proton on benzaldehyde, while I think that the conjugation effect contribute mostly to the solution but the ortho hydrogen seems to be more deshielded than para one. What is the reason?

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