One-pot synthesis of short-chain cyclic acetals via tandem hydroformylation-acetalization under biphasic conditions

A novel method for the synthesis of 2-ethyl-1,3-dioxolane and related short-chain acetals by tandem hydroformylation–acetalization of ethylene is described. The reaction occurs in a biphasic system. The polar phase contains a catalytic system (Rh/TPPTS/H+), which is easy to separate and remains active when reused. Under optimized conditions the hydroformylation TOF reaches 1520 h−1 with an acetal selectivity of 90%. How the pH value, temperature, solvent and structure of the starting polyols influence the efficiency and selectivity of the tandem reaction is shown.