# Cationic Cascade Strategy for the Synthesis of Dihydrobenzofuran and Isochromane Scaffolds

## TL;DR

A new chemical method creates complex oxygen-containing ring structures important for drug development.

## Contribution

A stereospecific cascade reaction for synthesizing dihydrobenzofuran and isochromane scaffolds using enyne and carbonyl precursors.

## Key findings

- A Brønsted-acid-promoted cascade reaction enables the synthesis of oxygen heterocycles.
- The method allows de novo construction of dihydrobenzofuran and isochromane scaffolds.
- Late-stage functionalization is achieved alongside heterocycle formation.

## Abstract

Oxygen heterocycles are valued for their prevalence in
bioactive
molecules and their metabolic stability. We report a Brønsted-acid-promoted,
oxygen-interrupted halo-Prins/halo-Nazarov cascade that enables the stereospecific construction of
dihydrobenzofuran and isochromane scaffolds from simple enyne and
carbonyl precursors. This approach unites de novo heterocycle construction with late-stage functionalization, providing
access to complex oxygen heterocycles of relevance to medicinal chemistry.