ChemInform Abstract: Neoflor (Ia) and 6-Epineoflor (Ib) from Flowers of Trollius europaeus; Highfield 1H NMR Spectra of (all-E)-Neoxanthin (IIa) and (9′Z)-Neoxanthin (IIb).
The assignment of 13C and 1H NMR signals of synthetic (25 R)-5α-spirostanes is presented; the main effects on chemical shifts due to substitution at C-23 are briefly discussed.