(organic chemistry) An organic compound containing a hydroxyl group bonded to a carbon atom which is doubly bonded to another carbon atom.
1996, Ludvik Labler, August Rüttimann, Alfred Giger, Chapter 2: Coupling Reactions: Part I: Enol Ether and Aldol Condensations, George Britton, Synnove Liaaen-Jensen, Hanspeter Pfander (editors), Carotenoids, Volume 2: Synthesis, Springer (Birkhäuser), page 27,
Since research on the total synthesis of carotenoids began, the enol ether and the aldol condensations have been frequently used for the formation of carbon-carbon double bonds.