2,4-Dimethyl-6-oxo-2,4-cyclohexadienylidenediacetate

    Parameter     ppm  Hz

      D(A)         6.11
      D(B)         6.15
      D(C)         2.06
      D(D)         1.92
       J(A,B)          1.5
       J(A,C)          1.5
       J(A,D)          0.0
       J(B,C)          0.0
       J(B,D)          1.5
       J(C,D)          0.0
     
      D(E)         2.04
     
     BUBB,W.A. ET AL. ORG.MAGN.RESON. 9, 167 (1977)