A method for preparing saturated partially fluorinated alkoxy carboxylic acids or salts thereof by treating a compound: (II), where Rf represents a fluorinated, linear or branched alkyl residue interruptible by one or more oxygen atoms, n is 0 or 1, with a Z-anion in a reaction medium comprising water and an organic solvent, where the Z-anion is selected from CN—, SCN— and OCN— or combinations thereof. A method of making partially fluorinated ethers of the general formula (I) wherein Rf is defined as above, n is 0 or 1, and Z is nitrile (—CN), azide (—N3), thiocyanate (—SCN) or cyanate (—OCN) group, said method comprising treating a fluorinated olefin of the general formula (II) wherein the Z-anion is CN—, OCN—, SCN— or N3−. A compound of the general formula (I) as previously described where Z is selected from SCN, OCN and N3.