orthonym.validation.spelling.checks_identical_prefixes#

Note

Internal API. Names and behaviour may change between releases.

Spelling check of identical prefixes of one scope (registered with orthonym.validation.pin_spelling.register()).

A round trip proves the molecule, never the spelling: OPSIN reads ‘2-(4-methoxyphenyl)-2-methyl-N- methylpropanamide’ back to the structure of the preferred ‘2-(4-methoxyphenyl)-N,2-dimethylpropanamide’. A name that cites one substituent twice in one scope is the general spelling of a name the Blue Book writes with a multiplying prefix.

  • (the Blue Book), under “MULTIPLICATIVE PREFIXES ‘DI’, ‘TRI’, ETC. vs. ‘BIS’, ‘TRIS’, ETC.” (:7025): “Multiplicative prefixes… are the principal method for describing a multiplicity of identical features of a structure in chemical names.” The group takes the locants of all its members, the italic N cited before the numerals,:3195, “Italic capital and lower-case letter locants are lower than Greek letter locants, which, in turn, are lower than numerals”): ‘N,4-dimethyl-N-(3-methylphenyl)benzamide (PIN)’ (:32879), ‘N,N,2-trimethyl-3-{…} propanamide (PIN)’ (:21624). (:3448): multiplicative prefixes “do not alter the alphabetical order already established”, so the one group takes the place of its members.

The scope is a unit of the name as:mod:.units reads it: a word, or the content of one substituent enclosure (‘’,:2869, “the parent structure or… a unit of structure as defined by its appropriate enclosing marks”). Two prefixes with locants that name the same substituent in one unit break the rule: a simple prefix by its word (‘methyl’, and ‘tert-butyl’ apart from ‘butyl’), an enclosed prefix by its complete text, stereodescriptors included, so ‘[(1R)-1-hydroxyethyl]’ and ‘[(1S)-1-hydroxyethyl]’ are two substituents. A prefix without a locant is part of a compound word (‘ethoxyethoxy’) and is not counted. A unit with an isotope descriptor is not read: (:43718) makes ‘(13C)methyl’ another substituent than ‘methyl’ (‘2-(13C)methyl-3-methylpyridine’). The check reads the name text only; the structure is not used.

orthonym.validation.spelling.checks_identical_prefixes.identical_prefixes_check(mol, name)#

(:7027): a substituent cited twice in one scope is one multiplied prefix (‘N,2-dimethyl’, ‘2,3-dihydroxy’), never ‘2-methyl… N-methyl’.