title: Intramolecular Diels-Alder reactions of cyclopropenone ketals.
abstract: The first intramolecular cycloaddition reactions of cyclopropenone ketals with tethered electron-deficient, electron-rich, and neutral 1-substituted dienes are reported, constituting inverse electron demand, normal, and neutral Diels-Alder reactions, that provide exclusively the exo [4 + 2] cycloaddition products without the intervention of [1 + 2], [3 + 2], or [3 + 4] cycloadducts in reactions whose courses do not depend on the reaction conditions, the diene activating substituent, or the nature of the tethering.
authors.affiliation: Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
authors.forename: Paresma R
authors.initials: PR
authors.lastname: Patel
authors.forename: Dale L
authors.initials: DL
authors.lastname: Boger
mesh_terms: D003500:Cyclization; D003521:Cyclopropanes / Q000737:chemistry*; D004988:Ethers, Cyclic / Q000737:chemistry; D015394:Molecular Structure; D011090:Polyenes / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D003521:Cyclopropanes; D004988:Ethers, Cyclic; D011090:Polyenes; C120343:cyclopropenone