Question

Give the IUPAC nomenclature to each of the following molecules:

Answer 1

(i) (E)-oct-4-en-2-one, (ix) (E)-5-bromo-5-methyl-2-(tert-butyl)hex-4-en-3-one

Answer 2

For molecule (i), the longest carbon chain containing the ketone and the double bond has 8 carbons. Numbering from the end closest to the ketone, the ketone is at position 2 and the double bond is between positions 4 and 5. The stereochemistry of the double bond is (E).

For molecule (ix), the longest carbon chain containing the ketone has 6 carbons. Numbering from the end closest to the ketone, the ketone is at position 3, and the double bond is between positions 4 and 5. There is a bromine and a methyl group at position 5, and a tert-butyl group at position 2. The stereochemistry of the double bond is (E).