Abstract

An overview of the history of vitamin A is presented from its use in ancient times to structural elucidation in the 1930s. A description of commercially important retinoids and carotenoids is given. Owing to the presence of an extended polyene chain, the physical and chemical properties of these compounds are dominated by this feature and these characteristics are discussed. The current industrial syntheses of vitamin A as well as the syntheses of -carotene are compared and contrasted. A common element to the industrial preparation of vitamin A is that these processes have a common intermediate -ionone. Their differences lie in methodology to elaborate the side chain and in methods of preparation of -ionone. Biological aspects of vitamin A and -carotene in animal and plant systems are reviewed as well as important dietary sources of these substances. Analytical methodology is presented.