1,1,2,2-Tetramethylethylene glycol 2,3-Butanediol, 2,3-dimethyl- 2,3-Dimethyl-2,3-butanediol 4-01-00-02575 (Beilstein Handbook Reference) 52400-10-9 76-09-5 AI3-02251 BRN 1340501 EINECS 200-933-5 NSC 25943 PINACOL Pinacone Tetramethylethylene glycol