Investigation of a convergent route to purpuromycin: benzofuran formation vs spiroketalization.
[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.
Waters
Stephen P
SP
Department of Chemistry, Roy and Diana Vagelos Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA.
Fennie
Michael W
MW
Kozlowski
Marisa C
MC
D001572:Benzofurans / Q000138:chemical synthesis*; D015394:Molecular Structure; D009285:Naphthoquinones / Q000138:chemical synthesis; D013141:Spiro Compounds / Q000737:chemistry*
D001572:Benzofurans; D009285:Naphthoquinones; D013141:Spiro Compounds; C009115:purpuromycin; C105430:benzofuran