p-Toluenesulfonic acid → 1-(2-Tetrahydropyranyloxy)-2-octadecanol

Participants

Reaction Steps

A 1-liter flask equipped with a stirrer and dropping funnel was charged with 20 g (70 mmol) of octadecane-1,2-diol, 0.7 g (3.5 mmol) of p-toluenesulfonic acid and 350 ml of dichloromethane. While stirring the contents at room temperature, 5.9 g (70 mmol) of dihydropyran were added dropwise. After stirring the mixture at room temperature for 30 minutes, it was neutralized with NaHCO3 and concentrated under reduced pressure, and the resultant residue was then purified by column chromatography on silica gel, thereby obtaining 7.5 g (yield[: 29%) of 1-(2-tetrahydropyranyloxy)-2-octadecanol. This compound was charged into a 200-ml flask equipped with a stirrer, to which 5.1 g (50 mmol) of triethylamine and 50 ml of dichloromethane were added. Further, 3.8 g (33 mmol) of methanesulfonyl chloride were added at room temperature with stirring. After the resultant mixture was stirred at room temperature for 14 hours, the reaction mixture was added with water and subjected to extraction with dichloromethane, and the solvent was distilled off under reduced pressure. The resultant residue and 15 ml of dimethylformamide was charged into a 100-ml flask equipped with a stirrer, to which 5.5 g (83 mmol) of NaN3 were added. The contents were stirred at 90° C. for 1.5 hours. After cooling the reaction mixture to room temperature, it was added with water and subjected to extraction with chloroform, followed by concentration under reduced pressure. Thereafter, the resultant residue was purified by column chromatography on silica gel, thereby obtaining 7.1 g (yield: 90%) of an azide intermediate.

Provenance & Evidence