A nuclear magnetic resonance study of coleonol

Abstract

¹ H N.m.r. spectral assignments for the diterpenoid coleonol (1) have been made by two-dimensional methods. The earlier H-1 and H-6 chemical-shift assignments have been corrected and the structure has been reassigned. ¹³C N.m.r. spectra of (1) and of coleonol B (3) have been analysed with the help of two-dimensional ¹H–¹³C chemical-shift correlation, broad-band-decoupling, SFORD, DEPT, and specific-proton-decoupling techniques. Stereochemical information on structure (1) was obtained through stereospecific coupling constants and nuclear Overhauser effects.