Green and catalyst-free synthesis of deoxyarbutin in continuous-flow

Abstract

A one-step catalyst-free continuous-flow etherification protocol has been developed for the preparation of deoxyarbutin. The starting material hydroquinone was etherified with 3,4-dihydro-2H-pyran (DHP) to gain deoxyarbutin directly. A material recycling method was established to address the drawback of low per pass conversion which is caused by the reversible equilibrium of this reaction. The continuous-flow methodology is effective in inhibiting the double etherification side reaction to realize the facile and highly efficient preparation of deoxyarbutin.