Comparison of the Reaction of N-bromo-succinimide with Phytoene and Lycopersene

Abstract

IT is now well established that phytoene (I) is a precursor of the coloured carotenoids such as ζ-carotene and lycopene^1,2. If the biosynthesis of carotenoids were exactly analogous to that of sterols then lycopersene (II), the 40-C analogue of squalene, would be the first 40-C precursor formed. The consensus of opinion is that this compound is probably not a naturally occurring material and is not a carotenoid precursor^1,3–5; the opposite view is, however, held by Grob et al.^7,8. Zechmeister and Koe⁹ showed in 1954 that N-bromosuccinimide dehydrogenates phytoene to phytofluene (III) and ζ-carotene (IV), compounds now known to be intermediates between phytoene and lycopene (V). It was of importance to know what action N-bromosuccinimide, which imitates nature in its reaction with phytoene, would have on lycopersene under similar conditions.