Revisiting Hydroxyalkylation of Phenols with Cyclic Carbonates

Described is a tetrabutylammonium fluoride‐mediated hydroxyalkylation reaction of phenols with cyclic carbonates. This operationally simple method enables the synthesis of a variety of aryl β‐hydroxyethyl ethers in good to excellent yields with a very small amount of catalyst loading (0.1–1 mol%). Of particular note is the efficient conversion of aromatic diols and phloroglucinol to the corresponding bis‐ and tris‐hydroxyethylated products. To further showcase the versatility of this protocol, guaifenesin was prepared with a single step by the condensation of guaiacol and glycerol carbonate. We also developed a flow ethoxylation process permitting the continuous synthesis of multiflorol.