Efficient syntheses of three series of anionic gemini surfactants based on pentaerythritol are described. A series of disulfates was prepared by the double displacement of the two cyclic sulfates in the S 4-symmetric compound pentaerythritol spirobicyclic sulfate (1) with linear alkoxides. A second series of disulfates was prepared by reaction of the dialkoxides of di-O- alkylpentaerythritols with ethylene sulfate. The di-O-alkylpentaerythritols can be prepared ...