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dan2097 / opsin

Open Parser for Systematic IUPAC Nomenclature. Chemical name to structure conversion
https://opsin.ch.cam.ac.uk
MIT License
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Rejected: 1-phenyl-2-(pyrrolidin-1-yl){alkyl ketone} #116

Open dan2097 opened 5 years ago

dan2097 commented 5 years ago

Original report by Steve Chapman (Bitbucket: isomerdesign, ).

Rejects propanone and higher ketones with Atom is in unphysical valency state! Element: C valency: 5

Accepts 1-phenyl-2-(pyrrolidin-1-yl)ethanone
Accepts 1-phenyl-2-(pyrrolidin-1-yl)-1-propanone
Accepts 1-phenyl-2-(pyrrolidin-1-yl)propan-1-one

dan2097 commented 5 years ago

Original comment by Daniel Lowe (Bitbucket: dan2097, GitHub: dan2097).

This is caused by a long standing issue that all suffixes are currently applied before substitution, but really unlocanted suffixes needs to be applied after locanted substitution as the substitution can constrain where the suffixes may be placed. The “one” suffix is normally placed at the 2 position so that terms like propanone yield a ketone rather than an aldehyde. Due to the order of processing it doesn’t know that that the 2 position in these names is blocked by substitution.

1-phenyl-2-(pyrrolidin-1-yl)butanone is unambiguous, but assumedly 1-phenyl-2-(pyrrolidin-1-yl)pentanone and higher would be ambiguous?

dan2097 commented 5 years ago

Original comment by Steve Chapman (Bitbucket: isomerdesign, ).

Thanks Daniel, I appreciate the explanation.