Prefered IUPAC Name (hydrogen related)

For several calculations, MarvinSketch cannot distinguish between compounds like:

OS(O)=O

O[SH2](O)=O

Both smiles generate the same PIN, unless the valence is specified for the sulfur, the same SMILES is generated.

Thanks for your report. Which name would you expect for the second compound?

I don't know what the PIN is, all can I give is dihydrosulfurous acid as an idea. Alternatively, it could be called metasulfinic acid.

I expect the preferred organic name for that compound is something like:

dihydroxy-lambda6-sulfanone by analogy to PIN names chosen in sections like P-68.4.3.4 (iupac draft 2004)

ACD/Name and Lexichem produce dihydroxy-lambda4-sulfane oxide and dihydroxy(oxo)-lambda6-sulfane respectively which are both unambiguous names.

Thanks Daniel for the input. I agree with dihydroxy-lambda6-sulfanone. Actually, this became the generated name naturally, after fixing the false match on 'sulfurous acid'.

So this is now working in our development version, and should be released in version 5.5.1.

Brilliant. Will this be fixed for all similiar cases, or just sulfurous acid?

It should also be fixed for other sufur-based groups: sulfinic acid and thioperoxol. If you are aware of other problematic cases, please let us know.

I noticed that this problem is widespread, phosphorus-based groups are another example.