Late-Stage Conversion of a Metabolically Labile Aryl Methyl Ether-Containing Natural Product to Fluoroalkyl Analogues.

We report the conversion of aryl methyl ethers and phenols into six fluoroalkyl analogues through late-stage functionalization of a natural product-derived FDA-approved therapeutic. This series of short synthetic sequences exploits a combination of both modern and traditional methods and demonstrates that some recently reported methods do not always work as well as desired on a natural product-like scaffold. Nonetheless, reaction optimization can deliver sufficient quantities of each target analogue for medicinal chemistry purposes. In some cases, classical reactions and synthetic sequences still outcompete modern organofluorine transformations, which should encourage the continued search for improved reactions. Overall, the project provides a valuable synthetic roadmap for medicinal chemists to access a range of fluorinated therapeutic candidates with distinct physicochemical properties relative to the original O-based analogue.