Synthesis of Cycleanine Mono-<i>N</i>-oxides

Abstract

Oxidation of cycleanine (3) with m-chloroperbenzoic acid gave two diastereomeric N-oxides (1 and 2), and their stereochemistry was unambiguously determined on the basis of spectroscopic evidence. The NMR spectra of synthetic cycleanine mono-N-oxides 1 and 2 were significantly different from those of the natural product previously reported to be cycleanine N-oxide.