A facile construction of oxygen heterocycles by the reaction of benzoxepine-4-carboxylates with dihaloalkanes and activated alkynes

Abstract

This manuscript describes the preparation of heterocyclic compounds such as naphtho[1,3]-dioxoles (3a–h), [1,4]-dioxines (4a–h), [1,4]-dioxepines (5a–c), [1,4]-dioxocines (6a–c) and diethyl 2-(2-ethoxy-2-oxoethyl)naphtho[1,3]dioxoles (8a–f). These heterocyclic compounds have been achieved by the reaction of benzoxepine-4-carboxylates (1a–h) with dihaloalkanes (2a–e) and activated alkyne (7a) for the first time. This work represents the first example for the construction of utile oxygen heterocycles by the formation of C–C and C–O bonds in a one step process.