The first totalsynthesis of (−)-fructigenine A and a novel approach to (−)-5-N-acetylardeemin through a common imine intermediate (+)-3 are described. The key steps include highly enantioselective preparation of (+)-3 via domino olefination/isomerization/Claisen rearrangement (OIC) of 5, reductive cyclization (RC), and regioselective oxidation of (−)-4 and a novel assembly of the pyrazino ring of
Two alkaloids, fructigenines A (1) and B (2), have been isolated from Penicillium, fructigenum TAKEUCHI and the structures were established on the basis of spectroscopic evidence and chemical transformations.
根据光谱证据和化学变化,从竹内青霉中分离出了两种生物碱,即果实碱 A (1) 和 B (2),并确定了它们的结构。