Final answer:
The proper IUPAC name for 2-methyl-1-propanol is isobutanol because it gives clear locations for both the methyl group and the hydroxyl group, avoiding confusion that could arise from naming it 1-methylpropanol. The IUPAC nomenclature guidelines from 2013 encourage using an infix notation for functional group position to prevent ambiguity in larger or more complex molecules.
Step-by-step explanation:
The question discusses the proper IUPAC naming of the compound 2-methyl-1-propanol, commonly known as isobutanol, and why it is incorrect to name it as 1-methylpropanol. The naming issue arises because in IUPAC nomenclature, each part of the molecule's name serves a specific purpose in indicating its structure.
A name like 1-methylpropanol suggests that the methyl group is attached to the first carbon; however, without the numerical prefix before 'methyl', it could be confused with 1-methyl-propanol, in which the number refers to the location of another functional group, not the methyl group.
According to the rules set by the IUPAC nomenclature, the hydroxyl group (-OH) is given priority in numbering, which leads to the alcohol being named with the carbon chain numbered to give the hydroxyl group the smallest number. Therefore, 2-methyl-1-propanol is the correct name as it explicitly indicates the positions of both the methyl group and the hydroxyl group in the molecule.
The IUPAC updated their guidelines in 2013, requiring numbers indicating the position of functional groups to be used as an infix (propan-2-ol) rather than as a prefix (2-propanol). This helps to minimize confusion when naming molecules, as it clearly denotes the position of the hydroxyl group in alcohols. Over time, this new infix notation will become more familiar, but currently, both naming conventions are in use and understood in the chemical community.