Download ppt

Naming organic compounds
Pavla Balínová
Valence of elements in organic compounds:
C = always tetravalent
N = trivalent
O = bivalent
S = bivalent
H = monovalent
Halogens = monovalent
Classification of organic compounds:
1. Hydrocarbons
2. Derivatives of hydrocarbons
Hydrocarbons - overview
1) Aliphatic (acyclic) hydrocarbons
a) saturated - alkanes → ending: -ane (methane)
b) unsaturated - alkenes → ending: -ene (ethene)
- alkadienes → ending: -diene (butadiene)
- alkynes → ending: -yne (ethyne)
2) Cyclic hydrocarbons
a) alicyclic saturated - cycloalkanes → cyclo……ane (cyclopropane)
b) alicyclic unsaturated – cycloalkenes and cycloalkadienes
c) aromatic hydrocarbons = arens
(benzene and its derivatives)
Hydrocarbon rests (alkyls, R)
CH4
methane
→
CH3methyl
→
-CH2methylene
CH3-CH3
ethane
→
CH3-CH2ethyl
→
-CH2-CH2ethylene
CH2=CHvinyl
(ethenyl)
→
-CH=CHvinylene
CH2=CH2
→
ethene
(„ethylene“)
Aromatic hydrocarbons
benzene
naphthalene
anthracene
phenantrene
pyrene
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)
Important heterocyclic compounds
NITROGEN in the cycle
OXYGEN in the cycle
• pyrrole
• furane
• pyridine
• tetrahydrofurane
• pyrimidine
• pyrane
• purine
• tetrahydropyrane
• indole
• imidazole
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
derivative
formula
prefix
suffix
carboxylic acid - COOH
carboxy-
-oic acid
sulfonic acid
- SO3H
sulfo-
sulfonic acid
aldehyde
- CHO
formyl-
-al
ketone
= CO
oxo-
-one
alcohol
- OH
hydroxy-
-ol
thiol
- SH
sulfanyl-
-thiol
amine
- NH2
amino-
-amine
ether
- O -
R-oxy-
ether
sulfide
- S -
R-thio-
sulfide
halogen der.
- F, -Cl,
-Br, -I
halogen-
-
nitro-
-
nitro der.
- NO2
Rules for naming of organic compounds
●To find the longest unbranched chain containing the most
functional groups or to find the longest unbranched chain
containing the most double bonds or to find the longest unbranched
chain
• The main functional groups, multiple bonds and the other
substituents must obtain the lowest number locants as possible
Main functional group is the group with the highest position in the
„Table of functional groups“ ordering the groups according to their
„nomenclature importance“.
Derivatives of hydrocarbons
ALCOHOLS R-OH (R = alkyl)
Suffix: -ol (methanol, ethanol, …..) or alkyl + alcohol (ethyl alcohol)
Suffix: -diol (ethane-1,2-diol) or glycol (ethylene glycol)
Primary, secondary, tertiary alcohols
PHENOLS Ar-OH (Ar = aryl)
Common (trivial) names (phenol, pyrocatechol, resorcinol)
THIOLS (MERCAPTANES) R-SH
Suffix: -thiol (methanethiol) or Alkyl + mercaptan (methyl mercaptan)
ETHERS R1-O-R2 (R = alkyl or aryl)
Alkyl ether (ethyl methyl ether) ! alphabetic order !
or alkoxy + name of hydrocarbon (methoxyethane)
i.e. diethyl ether (common name „ether“)
SULFIDES R1-S-R2 (R = alkyl or aryl)
Alkyl sulfide (ethyl methyl sulfide)
ALDEHYDES R-CHO (R = H, alkyl or aryl)
Suffix: -al (methanal, ethanal, propanal, …)
! Trivial name of corresponding carboxylic acid + aldehyde
(formic acid → formaldehyde, acetic acid → acetaldehyde)
Cycloalkane carbaldehyde
KETONES R1-CO-R2 (R = alkyl or aryl)
Suffix: -one (propanone, butanone, ..) or alkyl + ketone
(dimethyl ketone)
! Trivial names (acetone) !
Diketones derived from arens: -quinone (1,4-benzoquinone)
AMINES are derived from ammonia: H(s) replaced by alkyl(s)
a) primary amines R-NH2
Alkylamine (methylamine)
b) secondary amines R1-NH-R2
Alkyl1(alkyl2)amine e. g. ethyl(methyl)amine ! alphabetic order !
N-alkylhydrocarbonamine (N-methylethanamine)
c) tertiary amines R1-NR2-R3
Alkyl1(alkyl2)alkyl3amine (trimethylamine)
NITROCOMPOUNDS R-NO2
Prefix: nitro-
(nitromethane, nitrobenzene)
SULFONIC ACIDS R-SO3H
Hydrocarbonsulfonic acid (benzensulfonic acid)
CARBOXYLIC ACIDS R-COOH
Suffix: -oic / -dioic acid
!!!Trivial names!!!
Saturated and unsaturated carboxylic acids
Mono-, di-, tri-carboxylic acids
Alpha α, beta β…….. carbon
Acyl / anion
Derivatives of carboxylic acids
1. Substitutional derivatives → substitution in the chain of an acid
1.1. Halogen derivatives R(X)-COOH X = halogen (Cl, Br,..)
Prefix: chloro-, bromo-, iodo-, fluoro1.2. Hydroxy derivatives R(OH)-COOH
Prefix: hydroxy!!Trivial names!! (lactic acid, malic acid, citric acid)
1.3. Oxo derivatives R(C=O)-COOH
Prefix: oxo- / keto!!Trivial names!! (pyruvic acid)
1.4. Amino derivatives R(NH2)- COOH
Prefix: amino!!Trivial names of amino acids!! (glycine, alanine, leucine, ..)
2. Functional derivatives of carboxylic acids → functional (carboxyl)
group is changed
2.1. Salts R-COO-M+ (M+ = metal cation)
Suffix: -ate / -oate
-ic → -ate / -oic → -oate
R-COO- = anion of carboxylic acid
Full name: cation carboxylate (sodium acetate)
2.2. Esters R1-O-CO-R2
(R1- = alkyl from alcohol)
suffix: -ate/-oate
Full name: alkyl carboxylate (methyl acetate, ethyl ethanoate)
2.3. Anhydrides R1-CO-O-CO-R2
Acid → anhydride (acetic acid → acetic anhydride)
2.4. Amides R-CO-NH2
Suffix: -amide (ethanamide)
-ic or –oic acid → -amide (formamide, acetamide)
2.5. Acylhalides R-CO-X (X = halogen)
Acyl name + halide (acetyl chloride)
2.6. Nitriles R-CΞN
Hydrocarbon + suffix: -nitrile (ethanenitrile /acetonitrile)
Alkyl cyanide (methyl cyanide)
Organic reactions
•Addition reactions: 2 or more molecules combine to form a larger
one
Hydration: addition of water
i. e. fumarate + H2O → malate
Hydrogenation: addition of H2 usually to unsaturated organic
compounds
i.e. CH2=CH2 + H2 → CH3-CH3
Unsaturated fatty acids (in oils) can be converted to solid fats
(margarine)
Halogen addition
● Elimination reactions:
Dehydration = loss of H2O from reacting molecule
i.e. conversion of alcohols to ethers 2 R-OH → R-O-R + H2O
i.e. conversion of carboxylic acids to anhydrides
2 R-COOH → R-CO-O-CO-R + H2O
•
Substitution reactions – a functional group in a
particular compound is replaced by another group
i.e. carboxylic acids → chlorides, amides of carboxylic
acids
• Rearrangement reactions – position of functional
group is rearranged to give a structural isomer of the
original molecule
i.e. citrate → isocitrate
Redox reactions: many redox reactions in organic
chemistry have coupling mechanism involving free
radicals intermediates (peroxides, superoxides O2-)
●