Question

The correct naming of the compound CH≡C-CH=CH-CH3 is __________

(a) Pent-3-en-1-yne

(b) Pent-2-en-4-yne

(c) Pent-3-ene-1-yne

(d) Pent-2-ene-4-yne

I have been asked this question during a job interview.

This interesting question is from Haloalkanes Nomenclature topic in division Haloalkanes and Haloarenes of Chemistry – Class 12

Answer 1

Correct option is (a) Pent-3-en-1-yne

Easiest explanation: The lower set of locants is 1, 3 rather than 2, 4. This compound is named as a derivative of alkyne and not alkenes. Also, the terminal ‘e’ in ene is dropped because it comes before ‘y’ of yne.