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

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