Complete 1H and 13C NMR structural assignments for five semi-synthetic eremantholides

Abstract

Five eremantholides were prepared from natural furanoheliangolides by reductions with Stryker's reagent, in previous works. We thus decided to perform a detailed and complete assignment of all 1H and 13C NMR data for those compounds. Through NMR experiments such as 1H NMR, 13C {1H} NMR, gCOSY, gHMQC, gHMBC, J-resolved, among others, it was achieved an unequivocal assignment of 1H and 13C NMR data for all studied substances, with measurement of all H/H homonuclear coupling constants and the clarification of all hydrogen signals multiplicities. Those data were not completely available yet in the literature.