Which of the following is the correct special suffix for the functional group when it is directly at — IUPAC and Nomenclature Chemistry Question

💡 Solution & Explanation

When a carbon-containing chain-terminating group is directly attached to a ring, or when three or more identical such groups are present on an unbranched chain, special suffixes are used. For the aldehyde group ($-CHO$), the special suffix is "carbaldehyde" because its carbon is excluded from the principal chain counting.