Total Syntheses of (+)-Aquatolide and Related Humulanolides

The short, efficient total synthesis of (+)-aquatolide was achieved by a biomimetic transannular [2+2] photocycloaddition, and provides the first example of constructing a 5/5/4/8-ring system from asteriscunolides. Furthermore, the reaction leading to a 5/4/4/7-ring system, the originally proposed structure of aquatolide, was also developed. This strategy achieved syntheses of five more humulanolides, (-)-asteriscunolides A, C, D, and I, and (+)-tetradehydroasteriscanolide.

Clavipines A–C, antiproliferative meroterpenoids with a fused azepine skeleton from the basidiomycete Clitocybe clavipes

Three novel meroterpenoids, clavipines A–C (1–3), possessing a benzoquinone fused to an azepine ring and a ten-membered carbocycle with α,β-epoxy/unsaturated-γ-lactone, were isolated from the basidiomycete Clitocybe clavipes.

Total Synthesis and Structure Revision of (±)-Clavilactone D Through Selective Cyclization of an α,β-Dicarbonyl Peroxide

The structure of (±)-clavilactone D was revised, and the synthesis was achieved in seven steps from a substituted benzaldehyde. The key step was the base-catalyzed cyclization of an α,β-carbonyl peroxide, which was obtained by an iron-catalyzed three-component reaction of a benzaldehyde, an alkene, and TBHP. NaBH₄-mediated reductive lactonization of the resulting cis-dicarbonyl epoxide led to the α,β-epoxy-γ-butyrolactone skeleton highly stereoselectively. The synthesis provides a concise, reliable, and practical route to the revised structure of clavilactone D.