New Synthesis of Natural Carotene Isorenieratene (<i>ϕ</i>,<i>ϕ</i>‐Carotene) and its 3,3′‐Dimethoxy Analogue

Abstract

Abstract The main pigments of Brevibacterium linens are the aromatic carotenoids 3,3′‐dihydroxyisorenieratene ( φ , φ ‐carotene‐3,3′‐diol), the corresponding monohydroxy compound, and the hydrocarbon isorenieratene. We report herein new syntheses of isorenieratene ( ϕ , ϕ ‐carotene) and its xanthophyll analogue, 3,3′‐dimethoxy‐ ϕ , ϕ ‐carotene, which may be considered a protected form of the natural xanthophyll, 3,3′‐dihydroxy‐ ϕ , ϕ ‐carotene.