title: Collective synthesis of humulanolides using a metathesis cascade reaction.
abstract: A new method has been developed for the concise and asymmetric synthesis of seven humulanolides in 5-7 steps without the need for protecting groups. Notably, the challenging 11-membered ring and bridged butenolide moieties in asteriscunolide D and 6,7,9,10-tetrahydroasteriscunolide were introduced in one step using a ring-opening/ring-closing metathesis cascade reaction. Asteriscunolide D was used as a versatile synthetic precursor to prepare asteriscunolides A-C via a photoinduced isomerization reaction, asteriscanolide via a unique transannular Michael reaction, and 6,7,9,10-tetradehydroasteriscanolide via a transannular Morita-Baylis-Hillman-type reaction. The unique bicyclo[6.3.0]undecane core was introduced diastereoselectively.
authors.affiliation: Department of Chemistry, South University of Science and Technology of China , Shenzhen 518055, China.
authors.forename: Jing-chun
authors.initials: JC
authors.lastname: Han
authors.forename: Fuzhuo
authors.initials: F
authors.lastname: Li
authors.forename: Chuang-chuang
authors.initials: CC
authors.lastname: Li
mesh_terms: D007783:Lactones / Q000138:chemical synthesis* / Q000737:chemistry; D008968:Molecular Conformation; D012717:Sesquiterpenes / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D007783:Lactones; D012717:Sesquiterpenes