Asymmetric Total synthesisof Asperones A and B throughOrganocatalyzed Quinone [5 + 2] Cycloaddition

The first asymmetric total synthesis of the anti-inflammatory polyketides asperones A (<b>1</b>) and B (<b>2</b>) has been accomplished. Key synthetic steps include a Diels–Alder and retro-Diels–Alder cascade to construct the poly substituted phenol, an Al-Salen-catalyzed asymmetric cyanosilylation to form the tertiary alcohol of gregatin A, and an organocatalyzed intermolecular [5 + 2] cycloaddition of <i>p</i>-quinone with electron-deficient alkenes to build the crucial [3.2.1] octane core of asperones A (<b>1</b>) and B (<b>2</b>).