title: A concise total synthesis of pyrovellerolactone using a rhodium-catalyzed [(3 + 2) + 2] carbocyclization reaction.
abstract: A concise and highly convergent three-step total synthesis of the lactarane natural product, pyrovellerolactone, is described. The key step involves a regio- and diastereoselective rhodium-catalyzed [(3 + 2) + 2] carbocyclization of an alkenylidenecyclopropane with a 4-hydroxybut-2-ynoate followed by an in situ intramolecular lactonization to generate the tricyclic core in a single operation. This represents the first example of a higher-order [3 + 2 + 2] carbocyclization reaction in total synthesis, which is likely to provide an important strategy for the construction of related targets within this sesquiterpene family.
authors.affiliation: Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, ON, K7L 3N6, Canada. Andrew.Evans@chem.queensu.ca
authors.forename: P Andrew
authors.initials: PA
authors.lastname: Evans
authors.forename: Phillip A
authors.initials: PA
authors.lastname: Inglesby
authors.forename: Kathryn
authors.initials: K
authors.lastname: Kilbride
mesh_terms: D001688:Biological Products / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D015394:Molecular Structure; D012238:Rhodium / Q000737:chemistry*; D012717:Sesquiterpenes / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D001688:Biological Products; D012717:Sesquiterpenes; C582453:pyrovellerolactone; D012238:Rhodium