Total Synthesis of 1'‐epi‐Septosones B and C and Discovery of Novel Compounds with Anti‐Cancer Activity

Comprehensive Summary Septosones B and C are a pair of polycyclic avarane‐type meroterpenoids which possess a distinctive spiro[4.5]decane backbone and exhibit promising biological activity. We report here the total synthesis of 1'‐ epi ‐septosones B and C through an unusual stereospecific 1,2‐alkyl migration of a 6/6‐fused dienone tertiary alcohol to a spiro[4.5]enedione scaffold. More importantly, two new compounds were found to exhibit potent anti‐cancer activity against Hep G2, MV‐4‐11, and MOLT‐4 cell lines with IC 50 values as low as 2.1 μM through bioactivity profiling of the synthetic advanced intermediates.