title: o-Quinone Methides via Oxone-Mediated Benzofuran Oxidative Dearomatization and Their Intramolecular Cycloaddition with Carbonyl Groups: An Expeditious Construction of the Central Tetracyclic Core of Integrastatins, Epicoccolide A, and Epicocconigrone A.
abstract: The intramolecular cycloaddition of o-quinone methides (o-QMs) with a carbonyl group has been envisaged and executed successfully in the context of constructing the complex and rare [6,6,6,6]-tetracyclic core found in the integrastatins, epicoccolide A, and epicocconigrone A. These transient o-QMs were generated easily from the oxidative dearomatization of the corresponding C2-(aryl)benzofuran by employing Oxone in acetone-water at rt. The subsequent cycloaddition with the carbonyl (or conjugated olefin) present on the C2-aryl group was spontaneous.
authors.affiliation: Division of Organic Chemistry, CSIR-National Chemical Laboratory , Dr. Homi Bhabha Road, Pune 411 008, India.
authors.forename: Atul A
authors.initials: AA
authors.lastname: More
authors.affiliation: Division of Organic Chemistry, CSIR-National Chemical Laboratory , Dr. Homi Bhabha Road, Pune 411 008, India.
authors.forename: Chepuri V
authors.initials: CV
authors.lastname: Ramana
mesh_terms: D001572:Benzofurans; D061565:Cycloaddition Reaction; D006572:Heterocyclic Compounds, Bridged-Ring / Q000737:chemistry*; D045563:Indolequinones / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D010084:Oxidation-Reduction; D013237:Stereoisomerism; D013464:Sulfuric Acids / Q000737:chemistry
chemical_list: D001572:Benzofurans; D006572:Heterocyclic Compounds, Bridged-Ring; D045563:Indolequinones; D013464:Sulfuric Acids; C000608209:epicoccolide A; C000608210:epicocconigrone A; C562141:integrastatin A; C068040:quinone methide; C562142:integrastatin B; C048813:potassium peroxymonosulfuric acid; C105430:benzofuran