# Does the reaction of 2‐hydroxy‐6‐methyl‐5‐nitrocyclohepta‐2,4,6‐trien‐1‐one with NaOH involve ring contraction?

What is the product and mechanism when 2‐hydroxy‐6‐methyl‐5‐nitrocyclohepta‐2,4,6‐trien‐1‐one is reacted with $$\ce{NaOH}$$?

The only reagent used is $$\ce{NaOH}$$ so I suppose it abstracts the acidic hydrogen from the $$\ce{-OH}$$ group. A nucleophilic attack at the carbonyl carbon is also possible, as it could form a tropylium like cation. But I am not sure as to how a ring contraction occurs. The final answer given is 3-methyl-4-nitrobenzoic acid. How does the formation of an acid group and the ring contraction take place?

• It may be worthwhile drawing the dicarbonyl tautomer and thinking of a possible C-H deprotonation, and also considering the mechanism of the Favorskii rearrangement. Apr 9, 2020 at 10:58
• Electrocyclization would get you to the Favorskii intermediate. Alternatively, the @Waylander diketone may undergo a benzylic acid rearrangement. Apr 9, 2020 at 19:13