title: Progress in the synthesis of the lituarines: stereocontrol in sequential C-C bond formation on a spirobutenolide template.
abstract: [structure: see text] We describe elaboration of a tricyclic spirobutenolide corresponding to the C(7-18) tricyclic substructure common to lituarines A-C. Conjugate addition, to install the C(16) methyl, is followed by construction of the crucial C(18-19) bond by silyl enol ether addition to the derived spiroacetal C(18)-O oxonium ion. Esterification with a C(1-6) acid, and selective ozonolysis to release the C(23) carbonyl, complete the assembly of all the carbons present in the lituarine macrocyclic core.
authors.affiliation: Department of Chemistry, University of Oxford, Chemistry Research Laboratory, UK. jeremy.robertson@chem.ox.ac.uk
authors.forename: Jeremy
authors.initials: J
authors.lastname: Robertson
authors.forename: Jonathan W P
authors.initials: JW
authors.lastname: Dallimore
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000737:chemistry; D002244:Carbon / Q000737:chemistry*; D004852:Epoxy Compounds / Q000138:chemical synthesis*; D047028:Macrocyclic Compounds / Q000737:chemistry; D015394:Molecular Structure; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D004852:Epoxy Compounds; D047028:Macrocyclic Compounds; D013141:Spiro Compounds; C442895:lituarine A; C442897:lituarine B; C442896:lituarine C; D002244:Carbon; C004511:butenolide; D015107:4-Butyrolactone