Stereocontrolled total synthesis and biological evaluation of (−)- and (+)-petrosin and its derivatives

Total synthesis of (−)- and (+)-petrosin was accomplished. Stereocontrolled construction of the quinolizidine ring was achieved through a diastereoselective Mannich reaction and an aza-Michael reaction. Head-to-tail dimerization was performed by assembly of the two monomers using Suzuki–Miyaura cross coupling and subsequent ring-closing metathesis to construct the 16-membered ring. Biological evaluation of synthetic (−)- and (+)-petrosin and its derivatives indicated that the bispiperidine structure was necessary for the inhibition of syncytium formation.