In the present paper is described a systematic study of poly-O-alkylation reactions of pentaerythritol (PE) and 1, 1, 1-tris (hydroxymethyl) ethane (TME) by 1, 4 Michael addition, under phase transfer catalysis (PTC), considering the effect of:(1) the organophilicity of PTC (three different catalysts were tested),(2) PTC concentration (from catalytic to equimolar conditions), and (3) the regime of addition of reactants coexisting in the aqueous phase of ...