High-Field ¹H-nmr Spectral Analysis of Some Cucurbitacins

Abstract

1H-nmr spectra of the natural products cucurbitacins A, B, C, D, E, F, I, L, 23, 24-dihydrocucurbitacin F, and hexanorcucurbitacin F, as well as three acetylated derivatives, were measured at 360 MHz in pyridine-d5. Chemical shifts and coupling constants were tabulated. In addition to all of the ring and side-chain protons, it was possible to assign several of the hydroxy group signals of these compounds. These compiled data should be useful for the structure determination of new compounds in this series.