output.sdf

     RDKit          2D

  3  2  0  0  0  0  0  0  0  0999 V2000
   -1.2990   -0.2500    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    0.0000    0.5000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    1.2990   -0.2500    0.0000 O   0  0  0  0  0  0  0  0  0  0  0  0
  1  2  1  0
  2  3  1  0
M  END
$$$$

     RDKit          2D

  5  4  0  0  0  0  0  0  0  0999 V2000
   -2.5981   -0.3000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
   -1.2990    0.4500    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    0.0000   -0.3000    0.0000 O   0  0  0  0  0  0  0  0  0  0  0  0
    1.2990    0.4500    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    2.5981   -0.3000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
  1  2  1  0
  2  3  1  0
  3  4  1  0
  4  5  1  0
M  END
$$$$

     RDKit          2D

  3  2  0  0  0  0  0  0  0  0999 V2000
   -1.2990   -0.2500    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    0.0000    0.5000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    1.2990   -0.2500    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
  1  2  1  0
  2  3  1  0
M  END
$$$$