n–butane on monobromination gives three isomers. The number of product(s) obtained when the major product is heated with $\mathrm{KOH} \mathrm{in} {\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{OH}$ is/are …..

Predict major product (final product) in the given sequence of reaction

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

Identify product $\mathrm{X}$ is:

The major product is

A hydrocarbon reacts with $\mathrm{HI}$ to give$\left(\mathrm{X}\right)$ which on reacting with aqueous $\mathrm{KOH}$ forms $\left(\mathrm{Y}\right)$. Oxidation of $\left(\mathrm{Y}\right)$gives $3-\text{methyl}-2-\text{butanone}.$
The hydrocarbon is:

Which of the following reaction is most suitable for preparation of ${\mathrm{PhCH}}_2{\mathrm{CHOHCH}}_3$

Which of the following order is correct for the decreasing reactivity to ring monobromination of the following compounds:

Electrophile $\stackrel{\oplus }{\mathrm{N}}{\mathrm{O}}_2$ attacks the following :

in which cases $\stackrel{\oplus }{\mathrm{N}}{\mathrm{O}}_2$ will attack at meta position.