title: Organocatalytic Michael addition-lactonisation of carboxylic acids using α,β-unsaturated trichloromethyl ketones as α,β-unsaturated ester equivalents.
abstract: Isothiourea HBTM-2.1 catalyses the Michael addition-lactonisation of 2-aryl and 2-alkenylacetic acids and α,β-unsaturated trichloromethyl ketones. Ring-opening of the resulting dihydropyranones and subsequent alcoholysis of the CCl3 ketone with an excess of methanol gives a range of diesters in high diastereo- and enantioselectivity (up to 95 : 5 dr and >99% ee). Sequential addition of two different nucleophiles to a dihydropyranone gives the corresponding differentially substituted diacid derivative.
authors.affiliation: EaStCHEM, School of Chemistry, University of St Andrews, North Haugh, St Andrews KY16 9ST, UK. ads10@st-andrews.ac.uk.
authors.forename: Louis C
authors.initials: LC
authors.lastname: Morrill
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Stark
authors.forename: James E
authors.initials: JE
authors.lastname: Taylor
authors.forename: Siobhan R
authors.initials: SR
authors.lastname: Smith
authors.forename: James A
authors.initials: JA
authors.lastname: Squires
authors.forename: Agathe C A
authors.initials: AC
authors.lastname: D'Hollander
authors.forename: Carmen
authors.initials: C
authors.lastname: Simal
authors.forename: Peter
authors.initials: P
authors.lastname: Shapland
authors.forename: Timothy J C
authors.initials: TJ
authors.lastname: O'Riordan
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Smith
mesh_terms: D002264:Carboxylic Acids / Q000737:chemistry*; D002384:Catalysis; D004952:Esters / Q000138:chemical synthesis* / Q000737:chemistry; D007659:Ketones / Q000737:chemistry*; D015394:Molecular Structure; D013890:Thiourea / Q000031:analogs & derivatives / Q000737:chemistry*
chemical_list: D002264:Carboxylic Acids; D004952:Esters; D007659:Ketones; D013890:Thiourea