Stereoselective Synthesis of the Eastern Quinolizidine Portion of Himeradine A

The synthesis of the C15–C17/N1′–C11′ quinolizidine portion of himeradine A is disclosed. An intramolecular, heteroatom Michael addition was employed to establish the C6′ stereogenic center with high diastereoselectivity. The quinolizidine ring was constructed using microwave-induced cyclization at the N1′–C2′ position. The C17 stereogenic center was introduced through a diastereoselective Overman rearrangement.