title: Diels-Alder cycloaddition and ring-closing metathesis: a versatile, stereoselective, and general route to embellished bridged bicyclic systems, carbocyclic framework of secoatisanes, and homologues.
abstract: A general and stereoselective methodology for the synthesis of bridged bicyclic octenones having various types of alkenyl chains and a tricyclic framework of secoatisanes and higher analogues is reported. In situ generation and cycloaddition of 2-allyl-6,6-spiroepoxycyclohexadienones with ethyl acrylate gave bicyclo[2.2.2]octanes having an allyl group at the bridgehead and other chemically distinguishable functionality in a regio- and stereoselective fashion. Selective manipulation of adducts led to the introduction of other olefinic chain of variable lengths at the carbon adjacent to the bridge head. Ring-closing metathesis in bicyclooctanes having olefin tethers provided an efficient route to tricyclic systems having bicyclo[2.2.2]octane framework having spiro-fused six-, seven-, and eight-membered rings.
authors.affiliation: Department of Chemistry, Indian Institute of Technology, Bombay, Mumbai 400 076, India. vks@chem.iitb.ac.in
authors.forename: Vishwakarma
authors.initials: V
authors.lastname: Singh
authors.forename: Pramod K
authors.initials: PK
authors.lastname: Sahu
authors.forename: Bharat C
authors.initials: BC
authors.lastname: Sahu
authors.forename: Shaikh M
authors.initials: SM
authors.lastname: Mobin
mesh_terms: D000473:Alkanes / Q000737:chemistry; D000475:Alkenes / Q000737:chemistry; D001643:Bridged Bicyclo Compounds / Q000737:chemistry*; D013237:Stereoisomerism; D013379:Substrate Specificity
chemical_list: D000473:Alkanes; D000475:Alkenes; D001643:Bridged Bicyclo Compounds; C024713:n-tetradecane; C007548:n-dodecane