Synthesen in der Carotinoid‐Reihe. 10. Mitteilung. Anwendung der <i>Wittig</i>‐Reaktion zur Synthese von Estern des Bixins und Crocetins

Abstract

Abstract A simple and efficient synthesis of norbixin and crocetin diesters is described following the schemes C 2 + C 2o + C 2 ,=C 24 and C 3 + C 14 + C 3 = C 20 respectively. By means of the Wittig reaction crocetin di‐aldehyde is condensed with a bromoacetic acid ester and a C 14 ‐dialdehyde with an α‐bromopropionic acid ester. The intermediate tri‐ phenylphosphorane compounds are crystalline and easily isolated in a pure state.