title: Catalytic enantioselective diversity-oriented synthesis of a small library of polyhydroxylated pyrans inspired from thiomarinol antibiotics.
abstract: A small library of 30 thiomarinol analogues was successfully synthesised using as a key step-a catalytic enantioselective tandem oxa[4+2] cycloaddition/aldehyde allylboration methodology. With this method, highly substituted α-hydroxyalkyl dihydropyrans were assembled in a single three-component reaction utilizing three different enol ethers and a wide variety of aldehydes, such as aromatic, heteroaromatic, unsaturated and aliphatic aldehydes. In a second operation, a mild and direct method for reducing an acetal unit in the α-hydroxyalkyl dihydropyrans was optimised without the need for protecting a nearby hydroxyl group. This procedure facilitated the synthetic sequence, which was completed by a dihydroxylation of the residual olefin of α-hydroxyalkyl 2H-pyrans to provide the desired library of dihydroxylated pyran analogues reminiscent of the thiomarinol antibiotics. The relative stereochemistry of the resulting library compounds was demonstrated by X-ray crystallography on one of the analogues.
authors.affiliation: Department of Chemistry, University of Alberta, Edmonton, AB , T6G 2G2, Canada.
authors.forename: Raed M
authors.initials: RM
authors.lastname: Al-Zoubi
authors.forename: Dennis G
authors.initials: DG
authors.lastname: Hall
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry*; D002384:Catalysis; D060326:Chemistry Techniques, Synthetic; D015394:Molecular Structure; D016712:Mupirocin / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D011714:Pyrans / Q000138:chemical synthesis / Q000737:chemistry*; D054852:Small Molecule Libraries
chemical_list: D000900:Anti-Bacterial Agents; D011714:Pyrans; D054852:Small Molecule Libraries; C085617:thiomarinol; D016712:Mupirocin