Exam Style Question - 2

Question: Give the IUPAC name of (CH₃)₂CHCH₂CH₂Br.Step 1: find the longest carbon chain that contains the functional group. Drawing it out shows a chain of four carbons with a methyl branch, so the stem is but-.Step 2: number the chain to give the functional group the lowest number. Numbering from the carbon attached to bromine makes the bromine carbon 1 and puts the methyl group on carbon 3.Step 3: put the prefixes in alphabetical order with their numbers. Bromo comes before methyl, so the IUPAC name is 1-bromo-3-methylbutane.Common errors are counting only the carbons written in a straight line, and numbering from the wrong end to give 4-bromo-2-methylbutane.