Synthese von optisch aktiven, natürlichen Carotinoiden und strukturell verwandten Naturprodukten. II. Synthese von (3 S, 3′S)‐Astaxanthin

Synthesis of optically active natural carotenoids and structurally related compounds. II. Synthesis of (3S, 3′S)‐astaxanthin The syntheses of rac. astaxanthin, (3 S, 3′S)‐astaxanthin (1), its 15‐cis isomer (21), its diacetate (22), and of (3 S, 3′ S)‐15, 15′‐didehydroastaxanthin (20) are reported.