Synthesen in der Carotinoid‐Reihe. 8. Mitteilung. Totalsynthese von Kryptoxanthin und eine weitere Synthese von Zeaxanthin

Abstract

Abstract Cryptoxanthin has been synthesized from acetoxy‐β‐C 19 ‐aldehyde and β‐C 21 ‐acetylenic carbinol following the scheme C 19 + C 21 = C 40 . The C 19 ‐aldehyde was obtained from keto‐iso‐C 14 ‐aldehyde via the acetoxy‐β‐C 14 ‐ and ‐C 14 ‐aldehydes. The optically inactive synthetic cryptoxanthin has the same melting point as the natural product, and the absorption spectra of the solutions are identical. Starting with the acetoxy‐β‐C 19 ‐aldehyde, an improved synthesis of zeaxanthin was developped, following the scheme C 19 + C 2 + C 19 .