Naming Organic Compounds

1. Naming Organic Compounds Vladimíra Kvasnicová

2. Carbon skeleton of organic compounds methane ethane hexane 3-methylpenthane

3. Organic compounds can be cyclic • C6: many conformations in space(free rotation of C-C; the most stable at room temperature: CHAIR conformation) http://www.chemistry.nmsu.edu/studntres/chem539/answers/chexane_chair.jpg http://cat.middlebury.edu/~chem/chemistry/students/williamson/stewart/chairboat.jpg

4. Substituentsin cyclic hydrocarbons • geometric isomerism =the same sequential arrangement of atoms but different arrangement in space trans = E- cis = Z- http://www.arthistoryclub.com/art_history/Geometric_isomerism

5. Double bond cannot rotate • example of geometric isomers: http://www.gunthersclass.com/24_10.jpg

6. NAMING ORGANIC COMPOUNDS Important prefixes:

7. Valence of elements in organic compounds • CARBON always tetravalent • NITROGEN trivalent • OXYGEN bivalent • SULPHUR bivalent • HYDROGEN monovalent • HALOGENS monovalent

8. Types of bonds: 1) single (-ane) saturated hydrocarbons 2) double (-ene) or triple (-yne) unsaturated hydrocarbons 3) conjugated (planar cycle: arens)

9. Hydrocarbon rests (alkyls, R) CH4→ CH3-→ -CH2- methane methylmethylene CH3-CH3→ CH3-CH2-→-CH2-CH2- ethane ethylethylene CH2=CH2→ CH2=CH- → -CH=CH- ethene vinylvinylene („ethylene“) (ethenyl)

10. Aromatic hydrocarbons = = = =benzene = = naphthalene = = anthracene

11. = = = phenanthrene = =pyrene = benzopyrene

12. Hydrocarbon rests of arens (aryls, Ar) → = = = benzene phenyl = = biphenyl → → benzoyl benzoic acid toluene benzyl

13. Important derivatives of benzene • methylbenzene = toluene • dimethylbenzenes = xylenes (o-, m-, p-) • 1,2-dimethylbenzene = o-xylene • 1,3-dimethylbenzene = m-xylene • 1,4-dimethylbenzene = p-xylene • vinylbenzene = styrene (→ polystyrene, PS)

14. NITROGEN in the cycle pyrrole pyridine pyrimidine purine indole imidazole OXYGEN in the cycle furan tetrahydrofuran pyran tetrahydropyran Important heterocyclic compounds

15. DERIVATIVES OF HYDROCARBONS The name of the compound is derived from the name of the basic unbranched hydrocarbon • principal functional group  type of the derivative  suffix • other functional groups → expressed by special prefixes + locants

19. DERIVATIVES OF HYDROCARBONS The name of the compound is derived from the name of the basic unbranched hydrocarbon ALCOHOLSR―OH(R = alkyl) • suffix: -ol(ethanol) • suffix: -diol (ethane-1,2-diol, ethylene glycol) • alkyl + alcohol (ethyl alcohol) • primary, secondary, tertiary alcohols • monofunctional / polyfunctional alcohols

20. THIOLS(MERCAPTANS) R―SH • suffix: -thiol(methanethiol) / -dithiol • alkyl mercaptan (methyl mercaptan) • alkyl hydrosulfide (methyl hydrosulfide) PHENOLSAr―OH(Ar = aryl) • common (trivial) names (phenol, cresols)

21. ETHERS R1―O―R2(R = alkyl or aryl) • alkyl ether (ethyl methyl ether) • alkoxyhydrocarbon (methoxyethane) SULFIDES R1―S―R2(R = alkyl or aryl) • alkyl sulfide (ethyl methyl sulfide)

22. ALDEHYDES R―CHO (R = H, alkyl or aryl) • suffix: -al(methanal) • carboxylic acid (trivial name) + aldehyde (formic acid → formaldehyde) • cycloalkane carbaldehyde

23. KETONES R1―CO―R2 (R = alkyl or aryl) • suffix: -one (propanone) • alkyl ketone (dimethyl ketone) • trivial names (acetone) • diketones derived from arens: -quinone

24. AMINES - derived from ammonia: H(s) replaced by alkyl(s) • primary: R―NH2 * alkylamine(methylamine) * hydrocarbonamine(methanamine) • secondary: R1―NH―R2 * alkyl1(alkyl2)amineethyl(methyl)amine * N-alkylhydrocarbonamine N-methylethanamine

25. tertiary: R1―NR2―R3 * alkyl1(alkyl2)alkyl3amine * alkyl1(alkyl2)hydrocarbonamine • quarternary ammonium base: 4 alkyls-N+ * (multiple)alkylammonium(= cation) e.g. tetramethylammonium-chloride CATION ANION --------------------------------------------------------------- + trivial names (aniline)

26. AZO DYES Ar1―N═N―Ar2 • hydrocarbon(larger one)azohydrocarbon • azohydrocarbon (Ar1 = Ar2) (azobenzene) NITROCOMPOUNDS R―NO2 • prefix: nitro-(nitromethane) SULFONIC ACIDS R―SO3H • hydrocarbonsulfonic acid (benzenesulfonic a.)

27. CARBOXYLIC ACIDS R―COOH • suffix: -oic / -dioic acid • trivial names! • saturated / unsaturated • mono-, di-, tri-carboxylic acids • alpha () / omega () carbon • - or n- fatty acids • acyl / anion

28. The figure was adopted from: J.Koolman, K.H.Röhm / Color Atlas of Biochemistry, 2nd edition, Thieme 2005

29. Derivatives of carboxylic acids 1. substitutional derivatives → substitution in the chain of an acid → no change in the carboxyl group 2. functional derivatives → functional (carboxyl) group is changed

30. Derivatives of carboxylic acids 1. substitutional derivatives → substitution in the chain of an acid 1.1. HALOGEN DERIVATIVES R(X)―COOH • prefix: chloro-, bromo-, iodo-, fluoro- 1.2. HYDROXY DERIVATIVES R(OH)―COOH • prefix: hydroxy- • trivial names!

31. 1.3. OXO DERIVATIVES R― (C═O)―COOH • prefix: oxo- / keto- • trivial names! 1.4. AMINO DERIVATIVES R(NH2)―COOH • prefix: amino- • trivial names!

32. 2. functional derivatives → functional (carboxyl) group is changed 2.1. SALTS R―COO- M+(M+ = metal cation) • suffix: -ate / -oate • -ic → -ate / -oic → -oate • R―COO- = carboxylate (anion of c.a.) • full name: cation carboxylate (sodium acetate)

33. 2.2. ESTERS R1―O―C(O)―R2 • suffix: -ate • R1―O― = rest of alcohol • R1 = alkyl • full name: alkyl carboxylate (methyl acetate) 2.3. ANHYDRIDES R1―C(O)―O―C(O)―R2 • acid → anhydride • (acetic acid → acetic anhydride) • organic, organic-inorganic

34. 2.4. AMIDES R―C(O)―NH2 • suffix: -amide(ethanamide) • -ic or –oic acid → -amide (acetamide) • substituted –NH2 group: N-alkyl…amide 2.5. ACYLHALIDES R―C(O)―XX = halogen • acyl name + halide(acetyl chloride) 2.6. NITRILES R―CN • hydrocarbon + suffix: -nitrile(ethanenitrile) • alkyl cyanide (methyl cyanide)

35. Important chemical reaction of organic compounds • substitution (= replacement)CH4 + Cl2→ CH3Cl + HCl • addition(multiplicity of chemical bond is lowered)CH2=CH2 + H2O → CH3-CH2-OH • elimination(new multiple bond is often formed, small molecule is released)CH3-CH2-OH → CH2=CH2 + H2O • rearrangement (= formation of an isomer)CH2=C(OH)-COOH → CH3-C(O)-COOH

36. Important chemical reaction of organic compounds • oxidation: oxygenation, dehydrogenation • reduction: hydrogenation • hydration /dehydration • esterification / ester hydrolysis • dissociation of carboxylic acids • aldol condensation of two carbonyl compounds • condensationreaction(= two molecules combine to form larger molecule with elimination of a small molecule)