Example 2
4-(((3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl)oxy)methyl)-2-(2,2,2-trifluoroethoxy)-1,3-dioxolane. Tris(2,2,2-trifluoroethyl)orthoformate (50 g, 161 mmol, SynQuest Laboratories) and 3-[(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl)oxy]-1,2-propanediol (25 g, 57 mmol, Wako Chemicals) was dissolved in 800 mL of anhydrous cyclohexane (Aldrich) in a round bottom flask. Trifluorotoluene (Aldrich) was added in 5 mL portions until the solution was clear (30 mL). A catalytic amount of p-toluenesulfonic acid (Aldrich) was added to the flask along with a Teflon coated magnetic stirbar. The flask was fitted with a Dean-Stark distillation head. The reaction was slowly heated to reflux and the trifluoroethanol was removed by azeotropic distillation at a boiling point of 65° C. After 3 hours, the reaction was complete and the flask was cooled to room temperature. The reaction mixture was concentrated at reduced pressure on a rotary evaporator. The residual was purified by fractional distillation under reduced pressure (b.p.=95-100° C. at 0.05 mmHg), providing the title compound in 74% isolated yield.