title: Lewis acid-mediated generation of bicyclo[5.3.0]decanes and bicyclo[4.3.0]nonanes.
abstract: [reactions: see text] Fragmentation of the cyclobutane-containing adducts generated from intramolecular cycloadditions of cyclobutadiene with olefins provides rapid entry into bicyclo[5.3.0]decane and bicyclo[4.3.0]nonane ring systems. Whereas earlier studies featured thermal methods to achieve the desired rearrangements, a mild, Lewis acid-mediated fragmentation has been identified for substrates with appropriate functionality adjacent to the strained ring system. The substrate scope and stereochemical outcome of the acid-mediated fragmentation are complementary to the thermal ring expansions, particularly in the case of the bicyclo[5.3.0]decanes.
authors.affiliation: Department of Chemistry, Eugene F. Merkert Chemistry Center, Boston College, 2609 Beacon Street, Chestnut Hill, Massachusetts 02467-3860, USA.
authors.forename: Holly L
authors.initials: HL
authors.lastname: Deak
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Williams
authors.forename: Marc L
authors.initials: ML
authors.lastname: Snapper
mesh_terms: D000473:Alkanes / Q000138:chemical synthesis* / Q000737:chemistry; D000475:Alkenes / Q000737:chemistry*; D001643:Bridged Bicyclo Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D007202:Indicators and Reagents; D007536:Isomerism; D015394:Molecular Structure; D011084:Polycyclic Aromatic Hydrocarbons / Q000138:chemical synthesis* / Q000737:chemistry; D013816:Thermodynamics
chemical_list: D000473:Alkanes; D000475:Alkenes; D001643:Bridged Bicyclo Compounds; D007202:Indicators and Reagents; D011084:Polycyclic Aromatic Hydrocarbons; C012867:decane; C017573:nonane