Question

For the following compound, write structural formula and IUPAC name for all possible isomers having the number of the double or triple bond as indicated:

C₅H₈ (one triple bond)

Answer 1

The following structural isomers are possible for C₅C₈ with one triple bond:

(I) \[\ce{H^1C ≡ ^3CH2 - ^4CH2 - ^5CH}\]

(II) \[\ce{H3^1C - ^2C ≡ ^3C - ^4CH2 - ^5CH3}\]

(III) \[\begin{array}{cc}
\ce{H3^4C - ^3CH - ^2C ≡ ^1CH}\\
|\phantom{......}\\
\ce{CH3}\phantom{....}\end{array}\]

The IUPAC name of

Compound (I) is Pent-1-yne,

Compound (II) is Pent-2-yne, and

Compound (III) is 3-Methylbut-1-yne.