potassium hydroxide in dimethyl sulfoxide T=90°C; 2.5 h;

1: 2,2'-lt;1,2-ethanediylbis(oxy)gt;bisphenol With caesium carbonate in acetonitrile 3 h; RefluxInert atmosphere; 2: 2,2'-(2,2'-oxybis(ethan-2,1-diyl)bis(oxy))bis(ethan-2,1-diyl)dimethansulfonate in acetonitrile Inert atmosphereReflux;

potassium hydroxide 1) isoamyl alcohol, boiled , water trap, 2) 10 h, boiled; Yield given. Multistep reaction;