Which of the following represent the correct IUPAC name for the compounds concerned : (i) But-3-yn-1-ol or But-4-ol-1-yne (ii) 4-Chloro-2-methylpentane or 2-Chloro-4-methylpentane (iii) 2, 2,-Dimethylpentane or 2-Dimethylpentane (iv) 2, 3- Dimethylpentane or 3, 4,-Dimethylpentane (v) 2, 4, 7- Trimethyloctane or 2, 5, 7-Trimethyloctane.

Which of the following represent the correct IUPAC name for the compou

1.	Which of the following represent the correct IUPAC name for the compounds concerned : (i) But-3-yn-1-ol or But-4-ol-1-yne (ii) 4-Chloro-2-methylpentane or 2-Chloro-4-methylpentane (iii) 2, 2,-Dimethylpentane or 2-Dimethylpentane (iv) 2, 3- Dimethylpentane or 3, 4,-Dimethylpentane (v) 2, 4, 7- Trimethyloctane or 2, 5, 7-Trimethyloctane.
Answer» Solution :(i) But -3- yn -1 ol : ` Hoverset(4)C = overset(3)C- overset(2)CH_2 - overset(1) CH_2 OH""`Functional group (-OH) gets preference in numbering the carbon chain. (ii) 2-Chloro--4-methylpentane : `""H_3 overset(1)C -UNDERSET(underset(CI)\|)overset(2)CH - overset(3)CH_2 - underset(underset(CH_3)\|)overset(4) CH - overset(5)CH_3""`Chloro substituent gets preference in numbering. (iii) 2, 2 -Dimethylpentane : `H_2 overset(1)C - underset(underset(CH_2)\|)overset(underset(2)overset(CH_2)\|)C - overset(3)CH_2 - overset(4) CH _2 -overset(5) CH_2""` Position of both the SUBSTITUENTS are indicated separately. (iv) 2, 3-Dimethylpentane : `overset(1) CH_3 - overset(2)underset(underset(CH_3)\|) CH - overset(3) underset(underset(CH_3)\|) CH - overset(4) CH_2 - overset(5) CH_2""` It has lowest set of locants. (v) 2, 4, 7-Trimethyloctane : `overset(1) CH_2 - underset(underset(CH_3)\|)overset(2) CH - overset(3)CH_2 - underset(underset(CH_3)\|)overset(4)CH- overset(5) CH_2 - overset(6) CH_6 - underset(underset(CH_3)\|)overset(7)CH -overset(8) CH_3""` It has lowest set of locants.