Phosphoric acid dimethyl 2-methyl-1-propenyl ester

    Parameter     ppm  Hz

      D(A)         6.22
      D(B)         1.64
       J(A,B)         -1.6
       J(A,X)          5.2
       J(B,X)          0.0
     
      D(D)         3.75
       J(D,X)         11.0
     
     GAYDOU,E.M. & LLINAS,J.R. ORG.MAGN.RESON. 6, 23 (1974)