Configuration of natural 9-hydroxyfuroeremophilane, its 9-hydroxy epimer and furanopetasin: NMR and CD studies

Abstract

The conformation and configuration analysis of cis- and trans-furoeremophilanes with hydroxy group in position 9, using 1H NMR and CD spectra, is discussed. Some steroid derivatives were used as models for CD study. A combination of both spectral methods gives complementary results. For natural 9-hydroxyfuroeremophilane the configuration 9β-OH was unequivocally proved and the originally proposed structure of furanopetasin corrected to VII.