Synthetic studies towards novel tetracyclic lycopodium alkaloids: A synthesis of deoxymagellaninone

Article abstract of DOI:10.1016/S0040-4020(98)00421-9

A short, novel, linear triquinane-based strategy, directed towards the synthesis of complex tetracyclic alkaloids of paniculatine and magellanine- type, and culminating in the synthesis of deoxymagellaninone 32 is delineated. The cornerstone of our approach was the utilization of the 'carbocycle-heterocycle equivalency' stratagem to generate the N- methylpiperidine ring-D from a cyclopentene precursor, e.g. 35→38. The six- membered ring-A present in the natural products was constructed either through cationic enone-olefin cyclization (25→26) or intramolecular Michael addition (34→35) protocols. Overall, the synthetic effort outlined here is notable for its brevity, conceptual simplicity and desirable levels of regio- and stereoselective control in various steps.