Facile access to novel chromeno-2,6,9-trioxabicyclo[3.3.1]nonadienes via tandem nucleophilic substitution and [4+2] hetero Diels–Alder reaction: experimental and theoretical study

Abstract

An efficient synthesis of novel chromeno-2,6,9-trioxabicyclo-[3.3.1]nonadienes (CTOBN) scaffolds was achieved by mild base mediated reaction of 4-chloro-3-formylcoumarin and o-hydroxyacetophenones. The structure of the product was confirmed by X-ray analysis and the proposed mechanism was validated computationally at B3LYP/6-31G(d) level.