Acetal compounds were synthesized by reaction of various alcohols and dibromomethane in an organic solvent and alkaline aqueous solution of KOH using quaternary ammonium salts as a phase‐transfer catalyst. We have greatly enhanced the efficiency of the reaction by adding quaternary ammonium salt in small proportions. A unique final product with two alkoxy substituents indicating a rapid second reaction was obtained in the organic phase. A pseudo‐first‐order rate law was used to describe the reaction only at large KOH concentration. At a small KOH concentration, the system was controlled by the chemical equilibrium of KOH and alcohol present at a limited concentration in the aqueous phase, whereas it was controlled by the reaction in the organic phase at a large concentration of KOH. The effects of the reaction conditions and parameters on the conversion of dibromomethane were investigated in detail. We have improved the reaction to obtain a high yield and a rapid rate by using a large concentration of KOH in a small volume of water and a solvent of appropriate polarity. Tetrabutylammonium bromide (TBAB) provides a high yield of product.