… cyclenic or cycloterpenic ketones . (1) Camphor (C 10 H 16 O)* . The heading covers both natural and synthetic … Colourless to amber‑yellow liquids. (6) Fenchone (C 10 H 16 O). Occurs in fennel and thuja oils. A clear, colourless … violet‑like odour. Used in perfumery. (8) Jasmone (C 11 H 16 O). Derived from jasmine‑blossom. A light yellow oil with …