Pubchem: getting canonical or isomeric smiles is sometimes not possible

[hechth]

For some molecules, pubchem doesn't distinguish between between isomeric and canonical SMILES and has only SMILES, making the retrieval fail. The functions to query canonical and isomeric smiles should be updated to supply the "standard" SMILES code if there is no distinction, therefore the queried ISOMERIC_SMILES or CANONICAL_SMILES should be filled with the value stored under SMILES if neither ISOMERIC_SMILES nor CANONICAL_SMILES are present.

[acquayefrank]

@hechth, could you kindly share an example of such a molecule and how to test it?