An oxygen substituted donor-acceptor cyclopropane (DAC) is used as a common intermediate in the enantiospecific collective total synthesis of butanolide- and butenolide-based natural products like (+)-juruenolide C and D, (+)-blastmycinone, (+)-antimycinone, and (+)-ancepsenolide. Enantiospecific first total syntheses of (+)-hydroxyancepsenolide and its acetate are achieved confirming their absolute stereochemistry.

Keywords:Total synthesis / Donor-acceptor systems / Small ring systems / Radical reactions / LactonesEnantioselective synthesis of Hagen's gland lactone is described. The enantiomerically enriched diol was prepared by organocatalytic α-oxidation of the aldehyde. The other key reactions involved a highly diastereoselective intramolecular

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The enantiospecific total synthesis of (+)‐3‐epi‐epohelmin was accomplished by rapid construction of the pyrrolizidine core starting from enantiopure l‐pyroglutamic acid. The key reaction included a highly regio‐ and stereoselective intramolecular cyclopropanation reaction, regioselective ring opening of a nitrogen‐substituted donor–acceptor cyclopropane, stereoselective reduction of a ketone, chemoselective organolithium addition to a Weinreb amide, and chemoselective oxidation of an allylic alcohol.

An intramolecular, stereoselective cyclopropanation of vinylogous carbonates with carbenes using copper catalyst is developed for the synthesis of donor‐acceptor substituted cyclopropapyranones. Completely regioselective ring cleavage of each of the cyclopropane bonds was achieved under suitable reaction conditions, leading to a diverse array of cyclic ethers. The developed method is utilized in the total synthesis of (±)‐diospongin B.