1H NMR study of the stereochemistry of lubimin and related vetispirane sesquiterpenoids

Abstract

The stereochemistry at C-2 and C-10 in lubimin, 15-dihydrolubimin and 3-hydroxylubimin derivatives has been investigated by ¹H NMR spectroscopy. Using parent compounds and acetyl derivatives (24 compounds) definitive spectroscopic assignments have been made. Nine oxidised derivatives (2- and 3-keto functionalisation) have also been investigated. The usefulness of diagnostic features in the spectra are illustrated and the conformational homogeneity of the series verified.