Accessing Complex Tetrahydrofurobenzo-Pyran/Furan Scaffolds <i>via</i> Lewis-Acid Catalyzed Bicyclization of Cyclopropane Carbaldehydes with Quinone Methides/Esters
Navpreet Kaur, Pankaj Kumar, Shiv Dutt, Prabal Banerjee
Abstract
Herein, we report a straightforward one-pot synthesis of tetrahydrofurobenzopyran and tetrahydrofurobenzofuran systems via an in situ ring-expansion of the cyclopropane carbaldehydes followed by a [2 + n] cycloaddition with the quinone derivatives. The transformation not only unveils a new reaction mode of cyclopropane carbaldehydes with quinone methides/esters, but also promotes a step-efficient diastereoselective route to the sophisticatedly fused oxygen tricycles that can be further dehydrogenated to access the valued dihydro-2H-furo[2,3-b]chromene frameworks.
Topics & Concepts
CyclopropaneChemistryPyranFuranQuinoneRing (chemistry)CycloadditionCatalysisLewis acids and basesDehydrogenationDominoCombinatorial chemistryStereochemistryMedicinal chemistryOrganic chemistrySynthesis of Indole DerivativesCatalytic Alkyne ReactionsCatalytic C–H Functionalization Methods