For the reaction: $CH_2=CH-CH=CH_2 + HBr (1 \text{ eq}) \xrightarrow{80^{\circ}C} P_1 + P_2$ (where $P_1$ is the major product),identify $P_1$.

The reaction of $4$-methyloct$-1-$ene $(P, 2.52 \ g)$ with $HBr$ in the presence of $(C_6H_5CO_2)_2O_2$ gives two isomeric bromides in a $9:1$ ratio,with a combined yield of $50 \%$. Of these,the entire amount of the primary alkyl bromide was reacted with an appropriate amount of diethylamine followed by treatment with aqueous $K_2CO_3$ to give a non-ionic product $S$ in $100 \% $ yield. The mass (in $mg$) of $S$ obtained is. . . . . . . [Use molar mass (in $g \ mol^{-1}$) : $H=1, C=12, N=14, Br=80$]

An unknown alkene $(A)$ reacts with $3 \ mole$ of $H_2$ gas in the presence of a platinum catalyst to form $1$-isopropyl-$4$-methylcyclohexane. When the unknown alkene $(A)$ is ozonized and reduced,the following products are obtained:
$HCHO$,$OHC-CH_2-CO-CO-CH_3$,and $CH_3-CO-CH_2-CHO$
What is the structure of alkene $(A)$?

Which of the following reagents cannot be used for the experimental reduction of a functional group?

Baeyer's reagent is used for the detection of

Product $(A)$ is