Carotenoids and related compounds. Part XXXIII. Synthesis of dehydroflexixanthin and deoxyflexixanthin

Abstract

The structures assigned to the two Flexibacter pigments flexixanthin (3,1′-dihydroxy-3′,4′-didehydro-1′,2′-dihydro-β,ψ-caroten-4-one) and deoxyflexixanthin (1′-hydroxy-3′,4′-didehydro-1′,2′-dihydro-β,ψ-caroten-4-one) have been confirmed by synthesis of the latter, and of dehydroflexixanthin (3,1′-dihydroxy-2,3,3′,4′-tetradehydro-1′,2′-dihydro-β,ψ-caroten-4-one), the autoxidation product of the former.