Total Synthesis and Structural Reassignment of Aranorosinol A, Aranorosinol B, and EI-2128‑1

Herein, we report a concise and collective
total synthesis of three
natural products aranorosinol A, aranorosinol B, and EI-2128-1 and
also the known penicimutanolone. A unified strategy was conceived,
which divergently accessed all four congeners within 9–11 steps
(LLS) from a common intermediate. Bisoxirane-directed 1,2-addition
was utilized as a key step to generate the desired configuration of
the C8 stereocenter of aranorosinol A and B, 28 years after
their first isolation, and these were both assigned as S configurations, while the C4′ and C6′ configurations of EI-2128-1 were both determined to be R,R-configurations.