Question

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

(a) 2,2-dimethylpentane or 2-dimethylpentane
(b) 2,4,7- trimethyloctane or 2,5,7-trimethyloctane
(c) 2-chloro-4-methylpentane or 4-chloro-2-methylpentane
(d) but-3-yn-1-ol or but-4-ol-1-yne.

Answer 1

The correct IUPAC names are 2,2-dimethylpentane, 2-chloro-4-methylpentane, and but-3-yn-1-ol. The correct name for trimethyloctane depends on the specific structure which isn't provided.

Step-by-step explanation:

The student has posed a question regarding the IUPAC nomenclature of various organic compounds. Here are the correct IUPAC names for the compounds mentioned:

1. 2,2-dimethylpentane is the correct name because both methyl groups are attached to the second carbon in the chain.
2. In the case of trimethyloctane, the correct name would depend on the positions of the methyl groups. Without knowing the structure, it is not possible to definitively answer whether 2,4,7-trimethyloctane or 2,5,7-trimethyloctane is correct.
3. When naming halogenated compounds, we choose the name which gives the lower number at the first point of difference. Therefore, 2-chloro-4-methylpentane is the correct name because the chlorine gets a lower number than the methyl group.
4. For compounds containing multiple functional groups, the functional group with the highest priority according to IUPAC rules is given the lowest possible number. Hence, but-3-yn-1-ol, which includes both an alkyne and an alcohol group, is correctly named because the alcohol (the higher priority group) receives the number one position.

It's also important to note that while working out the correct IUPAC names for compounds, one must consider the longest continuous carbon chain, the position of substituents and functional groups, and the application of the lowest number rule, where applicable.