Select the correct $IUPAC$ name of pyrogallol.

The $IUPAC$ name of the given compound is:

What is the correct structure of $4-$bromo$-3-$methylbut$-1-$ene?

Give $IUPAC$ names of the following compounds:
$(i)$ $CH_3-CH(Cl)-CH(CH_3)-CH(CH_3)-CH_2OH$
$(ii)$ $CH_3-CH(OCH_2CH_3)-CH_3$
$(iii)$ Structure of $2,6-$dimethylphenol
$(iv)$ Structure of $1-$ethoxy$-2-$nitrocyclohexane

The $IUPAC$ name of the compound $CH_3-CH(CH_2CH_3)-CH_2-CH(OH)-CH_3$ is

What is the $IUPAC$ name of the compound $CH_3 CH = CH - C \equiv CH$?