The determination, by 1H nuclear magnetic resonance studies, of some stereochemical features in the alkaloids isocorymine, erinine, erinicine, and eripine

Abstract

The structure of isocorymine (1a) has been confirmed and the relative stereochemistry at C-3 and C-16 for (1a), erinine (1b), erinicine (1c), and eripine (2a), at C-17 in (1a), and at C-19 in (1c), and the geometry of the 18,19-double bond in (1a), (1b) and (2a) elucidated by a combination of ¹H–¹H spin–spin coupling and nuclear Overhauser enhancement data measured at 300 MHz.