Synthesis of carotenoid-monosaccharide conjugates via azide–alkyne click-reaction

Abstract Carotenoid pentynoates were coupled to protected and unprotected sugar azides via an azide-alkyne click-reaction using bis-triphenylphosphano-copper(I)-butyrate (C 3 H 7 COOCu(PPh 3 ) 2 ) complex. Protected sugars delivered the conjugates with excellent yields, whereas with unprotected ones amphipathic carotenoid-sugar derivatives were obtained in good or moderate yields in a simple way.