Answer: Use of Etherificarion followed by fractional distinction.
Step-by-step explanation:
It is done by reacting a mixture of tetrahydrofurfuryl alcohol and up to about one equivalent of at least one low work function element, Reacting the said mixture with a halide; fractionally distilling said reacted mixture to yield the first distillate; reacting said first distillate with an excess amount of at least one low work function element; and, fractionally distilling said reacted first distillate to obtain the purified ether wherein said at least one low work function element is an elemental metal or a metal hydride which has a φ of less than about 3.0 eV.