title: A Brønsted acid mediated cascade enone synthesis from aldehydes containing a tethered propargylsilane.
abstract: MeSO3H effects the intramolecular allenylation of a series of aldehydes 1 to provide allenyl alcohol product 3 as a single diastereoisomer. Cyclization proceeds rapidly at -78 degrees C. However, when the reaction is performed at room temperature, aldehyde 1 provides enone product 7 instead. A mechanism for the formation of this product is proposed in which the initially formed allenyl alcohol 3 undergoes dehydration to provide an allyl carbocation, which is trapped with water, thereby installing the enone.
authors.affiliation: School of Chemistry, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
authors.forename: Rui
authors.initials: R
authors.lastname: Ramalho
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Jervis
authors.forename: Benson M
authors.initials: BM
authors.lastname: Kariuki
authors.forename: Alexander C
authors.initials: AC
authors.lastname: Humphries
authors.forename: Liam R
authors.initials: LR
authors.lastname: Cox
mesh_terms: D000143:Acids / Q000737:chemistry*; D000447:Aldehydes / Q000737:chemistry*
chemical_list: D000143:Acids; D000447:Aldehydes