Compound $\mathrm{P}$ on treatment with ${\mathrm{CH}}_2{\mathrm{N}}_2$ (diazomethane) produces compound $\mathrm{Q}$. Compound $\mathrm{Q}$ on reaction with $\mathrm{HI}$ produces two alkyl iodides $\mathrm{R}$ and $\mathrm{S}$. Alkyl iodide $\mathrm{S}$ with higher number of carbon atoms on reaction with $\mathrm{KCN}$ followed by hydrolysis gives $3$-methylbutanoic acid. The compound $\mathrm{P}$ is:

Which of the following represents the correct IUPAC name for the compound concerned?

2,2-Dimethylpentane or 2-Dimethylpentane

Which has highest percentage of enol content in the solution phase? Write the structure of enol of that compound.

(a) Acetone

(b) Acetophenone

(c) Acetic acid 

(d) Acetyl acetone

Which of the following will show tautomerism?

(P) $\mathrm{CH}-{\mathrm{CH}}_2-{\mathrm{CH}}_2-\mathrm{CHO}$

(Q) 

(R) 

(S) ${\mathrm{CH}}_2=\mathrm{CH}-\mathrm{OH}$

$\mathrm{L}$-Fucose with the following planar representation is a sugar component of the detorminants of the $\mathrm{A},\mathrm{B},\mathrm{O}$ blood group typing

The open chain structure of $\mathrm{L}$-Fucose can be represented as