A concise catalytic asymmetric approach to naturally occurring Amaryllidaceae alkaloids sharing a 5,10b-ethanophenanthridine skeleton [(–)-oxomaritidine, (–)-dihydromaritidine, (–)-maritidine, and (–)-epi-maritidine] has been envisioned. The key intermediate in this strategy was obtained by a Pd(0)-catalyzed decarboxylative allylation of a 2-arylcyclohexan-1-one-derived allylenol carbonate (87%, 96% ee).
Key words
Amaryllidaceae alkaloids - asymmetric total synthesis - oxomaritidine - dihydromaritidine - maritidine -
epi-maritidine