Give the structure of polyisoprene (natural rubber). Write down the ozonolysis of polyisoprene.

Limonene (${\mathrm{C}}_{10}{\mathrm{H}}_{16}$) is a naturally occurring hydrocarbon. It absorbs $2$ molecules of hydrogen for each molecule during hydrogenation. On ozonolysis followed by zinc dust and steam hydrolysis, it gives one mole of formaldehyde and one mole of tricarbonyl compound of following structure.

Give probable structure of limonene if it has a six membered ring.

In which reaction the product following Anti-Markovnikov's rule is observed?

Product P is 

${\mathrm{CH}}_3\mathrm{CH} = {\mathrm{CH}}_2 \underset{{\mathrm{H}}_2{\mathrm{O}}_2/{\mathrm{OH}}^{-}}{\overset{{\mathrm{BD}}_3/\mathrm{THF}}{\to }}\mathrm{X}$

Identify product $\mathrm{X}$ is:

cis$-2-$Butene $\stackrel{\mathrm{HOBr}}{\to }\mathrm{P}$

Identify product $\text{'}\mathrm{P}\text{'}$ is: