The cyclic alkene shown is treated with ozone and then with $\mathrm{Zn}$ and $\mathrm{H}{}_2\mathrm{O}$ (reductive work-up). Which structure is the organic product?

The compound shown is cyclohexene. Ozonolysis cleaves the ring double bond and each of the two carbons becomes a carbonyl carbon, so the ring opens to a six-carbon chain. Zn/H2O is a reductive work-up and stops at the aldehyde stage, giving hexanedial. The diacid would need $\mathrm{H}{}_2\mathrm{O}{}_2$ and the diol would need a hydride reductant.