Question

The IUPAC name of

Answer 1

We know that IUPAC naming is a method of naming organic compounds following the guidelines of International Union of Pure and Applied Chemistry (IUPAC). The format of an organic compound is prefix + word root + suffix.

Complete step by step answer:
Let’s discuss how to do IUPAC naming of an organic compound.

1. First we have to identify the longest carbon chain of the compound. The number of atoms in the longest carbon chain (parent chain) is the word root. For example, if five carbon atoms are present then the word root will be ‘pent’.

2. Then we have to number the carbon atoms of the parent chain in such a way that the carbon atom bonded to the functional group possesses the lowest number. The name of the functional group is the suffix.

3)The name of all other substituents is used as a prefix in the naming of the compound.

Now, come to the question. The given compound is,

First we have to number the carbon atoms of the parent chain. There are four carbon atoms in the compound. And the alkyne functional group is present at C2. And there are no other substituents present.

So, the IUPAC name of the compound is but-2-yne.

Note: Always remember that if more than one functional group is present in a compound, then the highest priority functional group should be considered functional groups and remaining functional groups should be considered as substituent. The decreasing order of priority of functional groups is,

$-COOH>-SO_3H>-COOR>-COCl,-CONH_2, -CN, -CHO, R-CO-R, -OH, -NH2, C=C, C≡C$