Asymmetric total synthesis of Lycopodium alkaloids α-obscurine, N-desmethyl-α-obscurine, β-obscurine and N-desmethyl-β-obscurine

Abstract

The asymmetric total synthesis of α-obscurine (1), β-obscurine (2), N-desmethyl-α-obscurine (3), and N-desmethyl-β-obscurine (4) was accomplished. Key reactions in the construction of the A/B/C-ring system include the Buchwald–Hartwig coupling reaction, the Heck cyclization, and the diastereoselective hydrogenation.