A Concise Route to Keto‐Bridged Polyphenols by Photo‐Fries Rearrangement in Flow

Abstract

Described is a new synthetic route to bis(2‐hydroxy‐3,5‐di‐t‐butylphenyl)methanone and its derivatives. The combined esterification/photo‐Fries rearrangement approach enables a modular preparation of keto‐bridged polyphenols. This protecting group‐free process is highly atom‐ and step‐economic, and a scalable production was easily achieved in the continuous‐flow mode.