Publisher Summary This chapter focuses on the brightly colored carotenoids that have aroused the curiosity of scientists since the beginning of organic chemistry and the first publications to deal with the carotenoids date from the early part of the 19th century. Most of the carotenoids have a trivial name, which is often derived from its natural origin and which gives no information on the structure. Carotenoids also occur as glycosides, glycosyl esters, and carotenoproteins and a special case are the sulfates in which the hydroxy group of the carotenoid is esterified with sulphuric acid. In principle, an almost countless number of strategies can be developed for the preparation of a carotenoid, but in reality, only a few strategies and methods have been worked out successfully and they have since been used repeatedly. Since carotenoid synthesis began, the enol ether condensation has frequently been used for the formation of carbon–carbon double bonds and this reaction was also applied for large-scale industrial production of carotenoids.