SELECTIVE HYDROGENATION OF CAROTENONES .2. REDUCTION OF RHODOXANTHIN TO LUTEIN AND ZEAXANTHIN, AND OF CANTHAXANTHIN TO A DIHYDRO-RETRO-CAROTENEDIOL BY TELLURIUM HYDRIDE

Racemic lutein and racemic zeaxanthin have been prepared from rhodoxan thin by reduction with tellurium hydride. Similarly, canthaxanthin was transformed into a retro-carotenediol.