orthonym.validation.spelling.checks_heterone#

Note

Internal API. Names and behaviour may change between releases.

Spelling check of the prefix ‘oxophosphanyl’: a heterone is a principal characteristic group (registered with:func:orthonym.validation.pin_spelling.register).

A round trip proves the molecule, never the spelling: OPSIN reads ‘{4-[(oxophosphanyl)oxy]phenyl} methanol’ back to the structure of the PIN ‘[4-(hydroxymethyl)phenoxy]phosphanone’. The check reads the RDKit structure and the name text only.

  • “HETERONES” (the Blue Book): “Compounds containing the -PO, -PO2, -AsO or -AsO2 are called heterones (see,. In the presence of a more senior characteristic group they are described by the compound prefixes oxophosphanyl,…”. The prefix is therefore correct only when a characteristic group senior to the heterone is present.

  • (:18162; items:18174-:18189): ‘ketones, pseudoketones and heterones’ are class 16, below the radicals and ions (1-4), acids, anhydrides, esters, acid halides, amides, hydrazides, imides, nitriles and aldehydes (5-15), and above hydroxy compounds (17), hydroperoxides (18), amines (19) and imines (20). (:29390): an acyclic heterone takes the suffix ‘one’ and that “leads to preferred IUPAC names”: ‘phenylphosphanone (PIN)’ (:28291).

  • Within class 16, (:29628): “There is no seniority order difference between ketones and pseudoketones. When necessary, the maximum number of carbonyl groups or doubly bonded oxygen atoms, the seniority order between chains and rings, and between rings and ring systems, are considered”. The count first,:18875): a parent that holds two or more ketone groups is senior to the phosphanone, which holds one. Then (:18917): “The senior parent structure, whether cyclic or acyclic, has the senior atom… N > P > As > Sb > Bi > Si > Ge > Sn > Pb > B > Al > Ga > In > Tl > O > S > Se > Te > C”, “A single senior atom is sufficient to give seniority to the parent hydride”. So a ketone whose parent hydride holds nitrogen keeps the prefix; a ketone on a carbon, oxygen or sulfur parent does not, the phosphanone is the parent.

  • “Pseudoketones” (:28258): “(a) cyclic compounds in which a carbonyl group in a ring is bonded to one or two skeletal heteroatoms”, ‘1,3-dioxan-2-one (PIN)’: a lactone, a cyclic carbonate and a cyclic urea are class-16 ketones with the ring as the parent hydride (the lactam, the imide and the cyclic urea of an N ring therefore keep the prefix; the lactone and the carbonate of an all-O ring do not). _CYCLIC_ESTER_IS_PSEUDOKETONE reads this once.

A name that cites the prefix for a structure whose senior class is below class 16, or is class 16 on a carbon, oxygen or sulfur parent, is a correct name that is not the PIN.

orthonym.validation.spelling.checks_heterone.heterone_prefix_check(mol, name)#

(:25977): ‘oxophosphanyl’ is the prefix of a heterone only in the presence of a more senior characteristic group. A name that cites it for a component in which the heterone is the principal characteristic group is not the PIN (the PIN is the phosphanone).