Synthesis, Isolation, and Full Spectroscopic Characterization of Eleven (<i>Z</i>)‐Isomers of (3<i>R</i>,3′<i>R</i>)‐Zeaxanthin

Abstract

Abstract Developmental efforts to improve the yield of the chemical synthesis of (3 R ,3′ R )‐zeaxanthin resulted in the isolation, partly by chromatography from reaction mixtures, and full spectroscopic characterization by 1 H‐NMR, UV/VIS, and CD spectrosocpy of eleven ( Z / E )‐isomers of zeaxanthin: (7 Z )‐, (9 Z ), (13 Z )‐, (15 Z )‐, (7 Z ,7′ Z )‐, (9 Z ,9′ Z )‐ (7 Z ,9 Z ,7 Z )‐, (7 Z ,11 Z ,7′ Z )‐, (9 Z ,13 Z ,9′ Z )‐, (7 Z ,9 Z ,7′ Z ,9′ Z )‐, and (7 Z ,9 Z ,11 Z ,7′ Z ,9′ Z )‐zeaxanthin. Five of these isomers were obtained by specific synthesis, namely the (7 Z )‐, (7 Z ,7′ Z )‐, (9 Z ,9′ Z )‐, (7 Z ,9 Z ,7′ Z )‐, and (7 Z ,9 Z ,7′ Z ‐9 Z )‐isomers.