title: Investigation of a convergent route to purpuromycin: benzofuran formation vs spiroketalization.
abstract: [Structure: see text] A mild and efficient [3+2] nitrile oxide/olefin cycloaddition allows coupling of the highly functionalized naphthalene and isocoumarin hemispheres of purpuromycin. A rationale of the inability of advanced keto alcohols to spirocyclize is presented based upon a systematic examination of the electronic factors present in these systems and suggests that the biosynthesis of purpuromycin does not proceed through open-chain intermediates.
authors.affiliation: Department of Chemistry, Roy and Diana Vagelos Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Waters
authors.forename: Michael W
authors.initials: MW
authors.lastname: Fennie
authors.forename: Marisa C
authors.initials: MC
authors.lastname: Kozlowski
mesh_terms: D001572:Benzofurans / Q000138:chemical synthesis*; D015394:Molecular Structure; D009285:Naphthoquinones / Q000138:chemical synthesis; D013141:Spiro Compounds / Q000737:chemistry*
chemical_list: D001572:Benzofurans; D009285:Naphthoquinones; D013141:Spiro Compounds; C009115:purpuromycin; C105430:benzofuran