Total Synthesis of (-)-Δ-lycorane

The total synthesis of (-)-delta-lycorane is reported. We performed organocatalytic Mannich reaction between phenylacetaldehyde and gamma-hydroxy lactam to construct a 5-substituted-2-pyrrolidone derivative in favor of the cis-isomer. Furthermore, diastereoselective conjugate addition to alpha,beta-unsaturated lactam was accomplished to obtain 4,5-disubstituted-2-pyrrolidone. The other salient features of this synthesis include Bischler-Napieralski reaction and ring closing metathesis. The total synthesis of (-)-delta-lycorane is reported.