The formic acid‐promoted thermal transformation of tertiary α‐acetylenic alcohols into α,β‐unsaturated ketones is generally known as the Rupe reaction. The study finds that in many cases, this reaction is competed by the Meyer–Schuster rearrangement, which also leads to the formation of α,β‐unsaturated ketones or aldehydes. But in certain cases, only the Rupe rearrangement takes place. This reaction is useful in the preparation of α,β‐unsaturated ketones.