Asymmetric Total synthesis of Asperones A and B through Organocatalyzed Quinone [5 + 2] Cycloaddition
Chunlei Qu1, Lu Chen1, Peng Wang1
1State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin 300071, China.
Abstract:
The first asymmetric total synthesis of the anti-inflammatory polyketides asperones A (1) and B (2) 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 p-quinone with electron-deficient alkenes to build the crucial [3.2.1] octane core of asperones A (1) and B (2).
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