Q.Identify the product formed in the reaction: acetophenone (C6H5-CO-CH3), treated with N2H4 / C2H5ONa (Wolff-Kishner conditions) -- a) 2-ethylcyclohexane (a cyclohexane ring bearing an ethyl group) b) the imine C6H5-CH=NH2 (a benzene ring conjugated to a C=NH2 group, drawn as an intermediate) c) ethyl benzoate (C6H5-CO-O-C2H5) d) ethylbenzene (C6H5-CH2-CH3)

Step 1. Acetophenone, C6H5-CO-CH3, is treated with N2H4 (hydrazine) and C2H5ONa (sodium ethoxide) -- exactly the reagent pair that defines the Wolff-Kishner reduction (Section 12.5.C.2).

Step 2. Mechanistically, the ketone first forms its hydrazone (C6H5-C(=N-NH2)-CH3) with the hydrazine, and that hydrazone then decomposes on heating with the strong base (sodium ethoxide), losing N2 gas and converting the former carbonyl carbon fully to a -CH2- group.

Step 3. So the C=O of acetophenone is reduced all the way to CH2, converting C6H5-CO-CH3 into C6H5-CH2-CH3 -- ethylbenzene. …

Recognise N2H4/C2H5ONa specifically as Wolff-Kishner conditions, which take a ketone's carbonyl all the way to a methylene group (full reduction to t …

• Stopping at the intermediate hydrazone/imine (option b) rather than carrying the mechanism through to its final, base-driven loss of N2 -- the whole point of Wolff-Kishner …