Illustrative of the partially protected reactant method, a polyol such as pentaerythritol, C(CH2 OH)4, is employed as the polyvalent core generating compound and is converted to alkali metal salt form, e.g., sodium or lithium, by reaction with alkali metal hydroxide or zero valence alkali metal and then reacted with a molar excess of a partially protected compound such as tosylate ester of 1-ethyl