Pd-Catalyzed Tandem [5 + 2] Cycloaddition/Ring Contraction of Phthalide-Derived Alkenes and Vinylethylene Carbonates for the Construction of Benzo-[5,5]-spiroketal Lactones
Qiang Xiong, Ji Lu, Liu Shi, Guang‐Yao Ran
Abstract
An annulation of phthalide-derived activated alkenes is initially disclosed in this work. Specifically, we have developed an unprecedented [5 + 2] cycloaddition/ring-contraction tandem process of activated tetrasubstituted alkenes derived from phthalides or butyrolactone with vinylethylene carbonates under Pd(0) catalysis. Differing from the traditional spirolactonization strategy, this method renders an efficient and mechanistically distinct approach to benzo-[5,5]-spiroketal lactones and [5,5]-spiroketal lactones bearing two vicinal tetrasubstituted centers with high diastereoselectivity.
Topics & Concepts
ChemistryPhthalideTandemCycloadditionAnnulationCatalysisStereochemistryContraction (grammar)Combinatorial chemistryMedicinal chemistryOrganic chemistryInternal medicineMaterials scienceMedicineComposite materialSynthesis of Indole DerivativesOxidative Organic Chemistry ReactionsCatalytic C–H Functionalization Methods