Water → 2-[2-(Heptafluoropropoxy)-tetrafluoroethyl]-ethyl alcohol

C3F7OCF2CF2CH2CH2OH was produced by charging C3F7OCF2CF2I (100 g, 0.24 mol) and benzoyl peroxide (3 g) to a pressure vessel under nitrogen. A series of three vacuum/nitrogen gas sequences was then executed at −50° C. and ethylene (18 g, 0.64 mol) was introduced. The vessel was heated for 24 hour at 110° C. The autoclave was cooled to 0° C. and opened after degassing. Then the product was collected in a bottle. The product was distilled giving 80 g of C3F7OCF2CF2CH2CH2I in 80% yield. The boiling point was 56-60° C. at 25 mm Hg (3333 Pa). A mixture of C3F7OCF2CF2CH2CH2I (300 g, 0.68 mol) and N-methyl-formamide (300 mL), was heated to 150° C. for 26 h. Then the reaction was cooled to 100° C., followed by the addition of water to separate the crude ester. Ethyl alcohol (77 mL) and p-toluene sulfonic acid (2.59 g) were added to the crude ester, and the reaction was stirred at 70° C. for 15 minutes. Then ethyl formate and ethyl alcohol were distilled out to give a crude product. The crude product was dissolved in ether, washed with aqueous sodium sulfite, water, and brine in turn, and then dried over magnesium sulfate. The product was then distilled to give 199 g of C3F7OCF2CF2CH2CH2OH in 85% yield. The boiling point was 71-73° C. at 40 mm Hg (5333 Pa).