Download the zipped version of the first installments of this series, originally published in the Sci-Tech Translation Journal, of the American Translators Association. The file is approximately 87 KB.
Previous installments of this series appeared in the July
1997, October 1997, January
1998, April 1998, and July
1998 issues of the Translation
Journal.
VI. Organic Sulfur Compounds (continued)
Thials, Thiones, and Thiocarboxylic Acids
Some examples of the sulfur
analogs of aldehydes, ketones, and
carboxylic acids are shown below:
Oxygen compounds | |
CH3CH2CH2CHO
| Butyraldehyde, or butanal |
CH3C(O)C2H5 | Methyl ethyl
ketone, or butanone |
CH3CH2C(O)OH | Propionic acid, or propanoic
acid |
HOC(O)CH2C(O)OH | Propanedicarboxylic acid, or malonic
acid
|
Sulfur analogs
|
CH3CH2CH2CHS
| Butanethial |
CH3C(S)C2H5 | Methyl ethyl
thioketone, or butanethione |
CH3CH2C(S)OH | Propanethioic
O-acid |
CH3CH2C(O)SH | Propanethioic
S-acid |
CH3CH2C(S)SH | Propanedithioic
acid |
HSC(S)CH2C(S)SH | Propanebis(dithioic)
acid |
Oxidized Organic Sulfur Compounds
We have seen that some organic oxygen compounds have sulfur analogs:
alcohols ROH » mercaptans RSH; ethers ROR' » sulfides RSR';
peroxides ROOR' » disulfides RSSR', and we have just looked at some
sulfur analogs of aldehydes, ketones, and carboxylic acids. However,
because sulfur compounds can readily be oxidized, there are further
classes of sulfur compounds with no oxygen analogs.
Dimethyl sulfide CH3SCH3 can be oxidized in stages to form two new compounds:
| | | |
| | | Dimethyl sulfoxide DMSO | | Dimethyl sulfone |
Sulfolane is a cyclic sulfone that is useful as a
solvent: | |
Oxidation of methyl mercaptan also proceeds stepwise:
|
|
|
|
|
| | | Methanesulfenic acid | | Methanesulfinic acid | | |
| Methanesulfonic acid |
Alkanesulfenic acids are unstable and cannot usually be isolated,
but sulfinic acids and sulfonic acids are stable compounds. The
simpler sulfur acids are given radicofunctional names as shown
above, but substitutive nomenclature may be more convenient for
complex compounds:
| |
4-Methyl-2-sulfinopentane, or
4-methyl-2-pentanesulfinic acid | 3-Sulfo-4-decene, or 4-decene-3-sulfonic acid |
Of course these acids can form salts and esters:
|
CH3CH2S(O)ONa | Sodium ethanesulfinate
(a salt) |
CH3S(O2)OC2H5 |
Ethyl methanesulfonate (an ester) |
Halides and anhydrides of sulfinic and sulfonic acids also exist:
|
CH3CH2CH2S(O)Br |
Propanesulfinyl bromide |
CH3S(O2)OS(O2)CH2CH3 | Methanesulfonic ethanesulfonic anhydride
|
| 3-Sulfopropionic anhydride
|
When some of the oxygen atoms attached to the sulfur atom in these
compounds are replaced by sulfur atoms, the prefix thio- (with
appropriate multiplier) is used:
| | Methanemonothiosulfonic
O-acid |
| Methanedithiosulfonic
S-acid |
Fortunately for translators, such compounds are rarely encountered
in the literature.
Before leaving the subject of sulfur compounds, a comparison of the
nomenclature of sulfuric acid derivatives and sulfonic acid
derivatives would not be out of place. As a dibasic (inorganic)
acid, sulfuric acid HOS(O2)OH can form monoesters, diesters, and
salts, all of which are called sulfates. The esters and salts of
sulfonic acids are of course called sulfonates. At first glance
their formulas may appear similar; they are differentiated by the
fact that only sulfonates have a carbon-to-sulfur bond:
CH3OS(O2)OCH3
| Dimethyl sulfate (a diester of sulfuric
acid) |
CH3S(O2)OCH3 | Methyl
methanesulfonate (an ester of
methanesulfonic acid) |
NaOS(O2)OC12H25 | Sodium
lauryl sulfate (a salt/ester of
sulfuric acid, and a widely used
surfactant) | |
VII. Alicyclic Compounds
Although other derivatives in the alkane series remain to be
discussed, especially nitrogen compounds, the descriptions given so
far of the compounds of carbon, hydrogen, halides, oxygen, and
sulfur in their infinite variety permit us to expand our
considerations to compounds in which the carbon atoms form rings.
The underlying cycloalkane series CnH2n, begins with
cyclopropane
C3H6:
Part XIV will continue the discussion of alicyclic compounds.
Readers are urged to e-mail questions, comments, or suggestions for further topics in the field of
organic nomenclature to the author at:
74654.1335@compuserve.com.
|