Hydrocarbons Part 1

On ozonolysis, unsaturated hydrocarbon X will form carbonyl compound, which gives positive Tollen's test. So, it should be aldehyde. (a) 2,3 -dimethylbut-2-ene undergoes ozonolysis reaction to give 2 molecules of acetone. (b) Isopropylidiene undergoes ozonolysis reaction to give acetone along with cyclopropanone. $\underset{\text{Isopropylidiene}}{\mathrm{CH}_3-\overset{\mathrm{CH}_3}{\overset{\vert}{\mathrm{C}}}=\triangle}\xrightarrow[\text{(ii) }\,\mathrm{Zn}/\mathrm{H}_2\mathrm{O}]{\text{(i) }\,\mathrm{O}_3}\underset{\text{Acetone}}{\mathrm{H}_3\mathrm{C}-\overset{\mathrm{CH}_3}{\overset{\vert}{\mathrm{C}}}=\mathrm{O}}\;\underset{\text{Cyclopropanone}}{+\mathrm{O}=\triangle}$ (c) Butyne reacts with $\mathrm{O}_3$ and $\mathrm{Zn}/\mathrm{H}_2\mathrm{O}$ to give 2-oxobutyraldehyde. The aldehyde will give Tollen's test to give silver mirror. Note Tollen's reagent contain silver nitrate $(\mathrm{AgNO}_3)$, ammonia and sodium hydroxide $(\mathrm{NaOH})$ which react with aldehydes to give $\mathrm{Ag}$ (silver mirror). (d) But-2-yne undergoes ozonolysis to give butan-2, 3-dione. Only product of option (c) contains aldehyde group.