Question

Which are the correct IUPAC names of the following compound?

• A. $5$-Ethyl-$4$-propyldecane
• B. $4$-($1$-methylethyl)-$5$-($1$-methylpropyl)-decane
• C. $5$-Butyl-$4$-isopropyldecane
• D. $5$-sec-Butyl-$4$-iso-propyldecane

Answer 1

Answer: (B), (D)

$5$-sec-Butyl-$4$-iso-propyldecane

Numbering as per IUPAC

The longest carbon chain is of 10 carbons along with one isopropyl group present at fourth carbon and one secondary butyl group present at fifth carbon.

Although IUPAC names for sec-butyl and isopropyl groups are $1$-methylpropyl and
$1$-methylethyl respectively, both these names are recommended for IUPAC nomenclature.

Hence, IUPAC name for the given alkane is:
$5$-sec-Butyl-$4$-isopropyldecane

or, $4$-($1$-Methylethyl)-$5$-($1$-methylpropyl)
decane.



Hence, options (C) and (D) are correct.