Question

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

a) But-3-yn-1-ol

b) But-4-ol-1-yne

Answer 1

The IUPAC names given in this question indicate that there are two functional groups present in the compounds. One is alkyne and other is alcohol. We know that alcohol has the more priority over the alkyne functional group. Hence, the carbon beating $-OH$ group should get the lowest possible number. Alcohol is represented by the suffix 'ol'. Hence the IUPAC name should have the lowest number prior to the suffix 'ol'.

Hence, the IUPAC name (a) is correct while (b) is incorrect.