General procedure for the synthesis of 1,3-benzodioxolane-4-alkylmethanol from methyl benzo[d][1,3]meso-dioxolane-4-carboxylate: 6.7 g (0.037 mol) of methyl benzo[d][1,3]meso-dioxolane-4-carboxylate was dissolved in 50 mL of tetrahydrofuran and 8.6 g (0.223 mol) of sodium borohydride was added. The temperature of the reaction system was raised to 65 °C and the reaction was continuously stirred for 30 min. Heating and stirring were stopped and 8 mL of methanol was added slowly and dropwise over 30 minutes. A large number of bubbles were observed to be generated during the reaction, after which the reaction mixture was refluxed for 4 hours. Upon completion of the reaction, the reaction was quenched with saturated ammonium chloride solution, the reaction mixture was filtered and the tetrahydrofuran was removed by distillation under reduced pressure. Ethyl acetate was added to the residue to partition the organic and aqueous phases, and the organic phase was washed with saturated brine and dried with anhydrous sodium sulfate for 8 hours. The desiccant was removed by filtration and the solvent was evaporated under reduced pressure to give 5.6 g of a white oily product, 1,3-benzodioxolane-4-alkylmethanol. Thin layer chromatography (TLC) analysis showed a single spot and the purity of the product met the requirements for subsequent reactions. The yield was close to 100%.
