Neoflor und 6‐Epineoflor aus Blüten von Trollius europaeus; Hochfeld‐1H‐NMR‐Spektren von Neoxanthin und (9′Z)‐Neoxanthin

Abstract
Neoflor and 6‐Epineoflor from Flowers of Trollius europaeus; Highfield 1H‐NMR Spectra of (all‐E)‐Neoxanthin and (9′Z)‐NeoxanthinRe‐isolation of the very polar carotenoids from flowers of the title plant furnished two epimeric pentahydroxy compounds. Based on spectroscopical and chiroptical arguments and by chemical correlation with neoxanthin, their structures were established as 11 (proposed name neoflor) and 12 (6epineoflor), Decoupling experiments and COSY‐2D‐1H‐NMR spectra allowed a complete assignement of the vinyl protons of the two isomers, and furthermore, for the first time, also of those of (all‐E)‐neoxanthin and (9′Z)‐neoxanthin.