title: Intramolecular Diels-Alder reactions of cycloalkenones: stereoselectivity, Lewis acid acceleration, and halogen substituent effects.
abstract: The intramolecular Diels-Alder reactions of cycloalkenones and terminal dienes occur with high endo stereoselectivity, both thermally and under Lewis-acidic conditions. Through computations, we show that steric repulsion and tether conformation govern the selectivity of the reaction, and incorporation of either BF3 or α-halogenation increases the rate of cycloaddition. With a longer tether, isomerization from a terminal diene to the more stable internal diene results in a more facile cycloaddition.
authors.affiliation: Department of Chemistry and Biochemistry, University of California-Los Angeles , 607 Charles E. Young Drive, Los Angeles, California 90095-1569, United States.
authors.forename: Hung V
authors.initials: HV
authors.lastname: Pham
authors.forename: Robert S
authors.initials: RS
authors.lastname: Paton
authors.forename: Audrey G
authors.initials: AG
authors.lastname: Ross
authors.forename: Samuel J
authors.initials: SJ
authors.lastname: Danishefsky
authors.forename: K N
authors.initials: KN
authors.lastname: Houk
mesh_terms: D002384:Catalysis; D003516:Cycloparaffins / Q000737:chemistry*; D006219:Halogens / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D058116:Lewis Acids / Q000737:chemistry*; D008958:Models, Molecular; D013816:Thermodynamics
chemical_list: D003516:Cycloparaffins; D006219:Halogens; D007659:Ketones; D058116:Lewis Acids