Question

For the following compounds, write structural formulas and IUPAC names for all possible isomers having the number of the double or triple bond as indicated :

(a) $C_4{H}_8$(one double bond)

(b)$C_5{H}_8$ (one triple bond)

Answer 1

Three isomers are possible. Their IUPAC names are

(I) $pent-1-yne$,

(II) $pent-2-yne$ and

(III) $3-methylbut-1-ene$.
The structural formulas are as shown.