What is the IUPAC name of the compound with the structure ${\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_{2}I$?

• A. $1$-iodopentane
• B. pentyl iodide
• C. $1$-iodobutane
• D. $2$-iodopentane

Answer: (A)

Verified step by step guidance

1. Identify the longest continuous carbon chain in the molecule. Here, the structure shows a chain of five carbon atoms, which corresponds to 'pentane' as the parent hydrocarbon.
2. Number the carbon chain starting from the end nearest to the substituent to give the substituent the lowest possible number. Since the iodine (I) atom is attached to one end of the chain, numbering from that end assigns it position 1.
3. Name the substituent attached to the main chain. The substituent is an iodine atom, which is named as 'iodo' in IUPAC nomenclature.
4. Combine the substituent name with the parent hydrocarbon name, placing the substituent number before the substituent name. This gives '1-iodopentane' as the IUPAC name.
5. Verify that no other substituents or functional groups are present that would change the parent name or numbering, confirming that '1-iodopentane' is the correct IUPAC name.