Notes relating to 'Draw This Structure'

The Draw This Structure JavaScript program allows minimally complex systematic IUPAC names to be converted to SMILES notation, and from there to a structural diagram.

Only a small subset of the actual IUPAC Nomenclature can be translated here. The focus here is specifically on substitutive and radicofunctional nomenclatures, since those are what most first-year students are exposed to and are responsible for. I have tried to include as many sorts of names in this program as feasible for a small JavaScript program. Many trivial names are NOT included. Examples of recognized names and limitations are given in the table below.

typeexamplelimitations
acyclic hydrocarbons 3-methylpentane
2-(4-methylhexyl)undecane
3-methylidene-1-heptyne
maximum chain length is 12 (dodecane)
names involving diyl, triyl, -2-yl, etc., are not recognized
cyclic hydrocarbons 1,3-dimethylcyclopentane
3-methyl-2-phenylnaphthylene
only the aromatic systems phenyl, benzyl, and naphthyl are recognized
ortho, meta, and para are not recognized
halides 1,2-dibromopentane
iodobenzene
dichloromethane
methyl bromide
methylene chloride
F through I are recognized
alcohols 2-pentanol
methanol
isopropyl alcohol
2-hydroxy-3-pentanone
2,3-pentanediol
3-methylphenol
names such as cresol and xylenol are not recognized
ethers methoxymethanol
diethyl ether
methyl ether
methyl ethyl ether
limited radicofunctional recognition (methyl ethyl ether)
amines triethylamine
isopropylamine
2-amino-3-pentanone
N,N-diethylmethylamine
4-(N,N-dimethylamino)pyridine
very complex amines may not be recognized
ketones 2-pentanone
3-hexen-2-one
2-oxopentanoic acid
methyl ethyl ketone
limited radicofunctional recognition (methyl butyl ketone)
carboxylic acids and derivatives benzoic acid
2-methylbutyl benzoate
methyl formate
isopropyl acetate
propanoyl chloride
limited to acids, esters, and acyl halides

Note that the IUPAC system of nomenclature is really a very complex beast, consisting of several nomenclatures, each with its own distinctive rules. Only the first two are recognized by this program.

substitutive(Pronounced, I believe, sub-STI-tu-tiv.) This is the "systematic" nomenclature generally taught to beginning organic chemistry students. Examples include 3-methylheptane and isopropanol.
radicofunctionalFor certain common chemicals, this IUPAC-approved system involves at least two words (at least in English): The first word is a radical, such as methyl or ethyl, and the last word is a functional group, such as alcohol. Suffixes such as ol are not used in radicofunctional names. Examples include methyl alcohol, methyl ethyl ketone and dimethyl ether.
additiveAdditive names such as styrene oxide consist of a word that is a complete chemical name followed by another word that adds functionality. Additive nomenclature is only recommended in specialized cases and is not generally appropriate.
subtractiveCertain chemical compounds are named as parent compounds from which has been removed one or more equivalents of H2 (anhydro), H2O (dehydro), O (deoxy), or CH2 (nor). Examples include 7,8-didehydrocholesterol, dehydro-L-ascorbic acid, and 3-deoxy-glucose
conjunctiveConjunctive names are complete names of compounds strung together as one word. For example, cyclohexanemethanol or 2-naphthalenepropanol. Conjunctive nomenclature always involves a ring attached to a chain bearing a functional group.
replacementA rarely used nomenclature that is allowed under the IUPAC system involves treating heteroatoms such as O and N in a chain as oxa or aza derivatives of the parent chain. For example, CH3OCH3 might in principal be called 2-oxapropane.
trivial namesNames that are in common usage but don't follow systematic rules. Examples include water and chlorophyl. Many such names are acceptable IUPAC names. They just aren't systematic IUPAC names.