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1 What is organic chemistry? I
l a Organic chemistryand this book 15
2 Organic structures 19
3 Determining organic structures 47
4 Structure of molecules 8 1
5 Organic reactions 113
6 Nucleophilic addition to the
carbonyl group 135
7 Delocalization and conjugation 151
8 Acidity, basicity, and pKa 181
9 Using organometallic reagents to
make C-C bonds 209
10 Conjugate addition 227
11 Proton nuclear magnetic
resonance 243
12 Nucleophilic substitution at the
carbonyl (C=O)group 279
13 Equilibria, rates, and mechanisms:
summary of mechanistic
principles 305
14 Nucleophilic substitution at C=O
with loss of carbonyl oxygen 339
15 Review of spectroscopic
methods 361
16 Stereochemistry 381
17 Nucleophilic substitution at
saturated carbon 407
18 Conformational analysis 447
19 Elimination reactions 477
20 Electrophilicaddition to
alkenes 503
21 Formation and reactions of enols
and enolates 523
22 Electrophilicaromatic
substitution 547
23 Electrophilicalkenes 581
24 Chemoselectivity: selective
reactions and protection 615
25 Synthesisin action 643
26 Alkylation of enolates 663
27 Reactions of enolates with
aldehydes and ketones: the aldol
reaction 689
28 Acylation at carbon 723
29 Conjugate addition of enolates 749
30 Retrosynthetic analysis 771
31 Controlling the geometry of
double bonds 803
32 Determination of stereochemistry
by spectroscopicmethods 823
33 Stereoselective reactions of cyclic
compounds 851
34 Diastereoselectivity 881
35 Pericyclic reactions 1:
cycloadditions 905
36 Pericyclic reactions 2: sigmatropic
and electrocyclicreactions 943
37 Rearrangements 969
38 Fragmentation 1003
39 Radical reactions 1019
40 Synthesis and reactions of
carbenes 1053
41 Determining reaction
mechanisms 1079
42 Saturated heterocycles and
stereoelectronics 1121
43 Aromatic heterocycles 1:
structures and reactions 1147
44 Aromatic heterocycles 2:
synthesis 1185
45 Asymmetric synthesis 1219
46 Organo-main-group chemistry1:
sulfur 1247
47 Organo-main-group chemistry 11:
boron, silicon, and tin 1277
48 Organometallicchemistry 1311
49 The chemistry of life 1345
50 Mechanisms in biological
chemistry 1381
51 Natural products 1413
52 Polymerization 1451
53 Organic chemistry today 1481
Index 1491
Addition of organometallic reagents to aldehydes and ketones 142 41 8 Additionketones ofwater^ to aldehydes^ and 143 Hemiacetals from reaction of alcohols with aldehydes and ketones 145 Acid and base catalysis of hemiacetal and hydrate formation 146 Bisulfite addition compounds 148 Problems 150
7 Delocalization and
conjugation 151
Introduction The structure of ethene (ethylene, CH2=CH2) Molecules with more than one C-C double bond Conjugation The ally1system Other allyl-lie systems
The conjugation oftwo n bonds
W a n d visible spectra Aromaticity 171 Problems 179
8 Acidity, basicity, and pK, 181
Introduction Acidity The definition of pKa Basicity 197 Neutral nitrogen bases 199 Neutral oxygen bases 203 pKa in action-the development of the drugcimetidine 204 Problems 207
9 Using organometallicreagents
to make G C bonds
Introduction Organometallic compounds contain a carbon-metal bond Making organometallics Using organometallicsto make organic molecules A closer lookat somemechanisms Problems
10 Conjugate addition
Conjugation changes the reactivity of carbonylgroups Alkenes conjugatedwith carbonyl groups are polarized Polarization is detectable spectroscopically Molecular orbitals control conjugate additions Ammonia and amines undergo conjugate addition Conjugate addition of alcohols can be catalysed by acid or base Conjugate addition or direct addition to the carbonyl group? Copper(1)salts have a remarkable effect on organometallic reagents Conclusion Problems
11 Proton nuclear magnetic
resonance
The differences between carbon and protonNMR Integration tells us the number of hydrogen atoms in each peak Regions of the proton NMR spectrum Protons on saturated carbon atoms
The alkene region and the benzene region The aldehyde region: unsaturated carbon bonded to oxygen Coupling in the proton NMRspectmm To conclude Problems
Catalysisin carbonyl substitution reactions 323 The hydrolysis of amides can have termolecular kinetics 325 The cistransisomerization of allcenes 326 Kinetic versus thermodynamic products 32s Lowtemperatures prevent unwanted reactions from occurring 331
12 Nucleophilic substitution at
the carbonyl (C=O) group
The product of nucleophilic addition to a carbonyl group is not always a stable compound
Solvents Summary of mechanisms from Chapters 6 1 2 Problems
14 Nucleophilic substitution at
C=O with loss of carbonyl
OxYgen
Introduction
Carboxylic acid derivatives Not all carboxylic acid derivatives are equally reactive Making other compounds by substitution reactions of acid derivatives (^) Aldehydes can react with alcoholsto Making ketones from esters: the problem form hemiacetals Making ketones from esters: the solution To summarize... And to conclude... Problems
Acetals are formed from aldehydes or ketonesplus alcoholsin the presence of acid Amines react with carbonyl compounds Amines from imines: reductive amination
13 Equilibria, rates, and
mechanisms: summary of
mechanistic principles
How far and how fast?
Substitution of C=O for C=C: abrieflook at the Wittigreaction Summary Problems
How the equilibrium constant varies with the differencein energybetween reactants and products How to make the equilibrium favour the product you want
15 Review of spectroscopic
methods 361
There are three reasons for this chapter 361 Does spectroscopyhelp with the chemistry of the carbonyl group? 361 Acid derivatives are best distinguished by infrared 364
Entropy is important in determining equilibrium constants Equilibrium constants varywith temperature Making reactions go faster: the real reason reactions are heated Kinetics
Small rings introduce strain inside the ring and higher s character outside it 365 Simple calculationsof C=O stretching frequenciesin IR spectra 367
E2 eliminationfromvinyl halides: how to make allcynes The regioselectivityof E2 eliminations Anion-stabilizinggroups allow another mechanism-ElcB To conclude... Problems
20 Electrophilic addition to
alkenes
Alkenes react with bromine Oxidation of alkenes to form epoxides Electrophilicaddition to unsymmetrical alkenes is regioselective Electrophilicaddition to dienes Unsymmetrical bromonium ions open regioselectively Electrophilicadditions to alkenes can be stereoselective Electrophilicaddition to allcenes can produce stereoisomers
Enolization is catalysed by acids and bases The intermediatein the base-catalysed reaction is the enolate ion Summaryof types of en01and enolate Stable enols Consequencesof enolization Reaction with enols or enolates as intermediates Stable enolate equivalents Enolandenolate reactions at oxygen: preparation of en01ethers Reactions of en01ethers To conclude... Problems
22 Electrophilic aromatic
substitution
Introduction: enols and phenols Benzene andits reaction with electrophies- Bromoniurn ions as intermediatesin (^) Electrophilic substitution on phenols stereoselectivesynthesis 516 Iodolactonizationand^ ~^ ~^ Anitroaenlonevair., -^ activates^ even^ more s t r o n ~ l v I
-..-.. bromolactonizationmake new rings 517 CT,
Alkyl benzenes react at the ortho and para
I I How to add water across a double bond 518 positions: o donor substituents
To conclude... 520 Problems 520
21 Formation and reactions of enols and enolates 523 Would you accept a mixture of compounds as apure substance? 523 Tautomerism: formation of enols by proton transfer 524 Why don't simplealdehydes and ketones exist as enols? 52s
Electronegativesubstituents give meta
products Halogens ( F , C1, Br, and I) both withdraw anddonate electrons Why do some reactions stop cleanly at monosubstitution? Review of important reactions including selectivity Electrophic substitution is the usual route to substituted aromatic compounds Problems Evidence for equilibration of carbonyl compoundswith enols 525
Compoundsthat can enolize but that are not electrophilic 696
enolates is apowerful synthetic transformation Conjugate addition of enolates is the result of thermodynamic control Avariety of electrophilic alkenes will accept enol(ate)nucleophiles Conjugate addition followed by cyclization makes six-membered rings
Controllingaldol reactionswith specific en01 equivalents 697 Specific en01 equivalents for carboxylic acid derivatives 704 Specificenolequivalents for aldehydes 707 Specific en01equivalents for ketones 709 The Mannich reaction 712 Intramolecular aldol reactions 715 To conclude: a summary of equilibrium and directed aldol methods 718 Problems 721
Nitroalkanes are superb at conjugate addition
30 Retrosynthetic analysis
Creativechemistry
28 Acylation at carbbn Retrosynthetic^ analysis: synthesis
backwards Introduction: the Claisen ester condensation compared to the aldol reaction
Disconnections must correspond to known, reliable reactions Problemswith acylation at carbon Synthons^ are^ idealized^ reagents Acylation of enolates by esters Choosingadisconnection Multiple step syntheses: avoid Crossed ester condensations chemoselectivityproblems Summary of preparation of keto-esters by the Claisen reaction Functional group interconversion Two-group disconnections are better Intramolecular crossedcondensations Claisen ester than one
Directed C-acylation of enols and^ G C^ disconnections enolates Donor and acceptor synthons Two-group C-C disconnections 1,5 Related functional groups 'Natural reactivity' and'umpolung' Problems
The acylation ofenamines Acylation of enols under acidic conditions Acylation at nucleophilic carbon (other than enols and enolates) How Nature makes fatty acids To conclude... Problems
31 Controlling the geometry of
double bonds
The properties of alkenes depend on their
29 Conjugate addition of
enolates
Elimination reactions are often unselective Introduction: conjugate addition of The^ Julia^ olefination^ is^ regiospecific^ and
and dicarbonyl compounds 1195 Pyrimidines can be made from 1,3-dicarbonylcompounds and amidines Unsymmetrical nucleophiies lead to selectivityquestions Isoxazoles are made from hydroxylamine or by 1,3-dipolarcycloadditions Tetrazoles are also made by 1,3-dipolar cycloadditions The Fischer indole synthesis Quinolimes and isoquinolines More heteroatoms in fused rings mean more choice in synthesis Summary:the three major approaches to the synthesis of aromatic heterocycles Problems
45 Asymmetric synthesis
Nature is asymmetrical-Nature in the looking-glass Resolution can be used to separate enantiomers The chiralpool-Nature's 'ready-made' chiral centres Asymmetric synthesis Chiral reagents and chiral catalysts Problems
46 Organo-main-group
chemistry 1: sulfur
Sulfur: an element of contradictions Sulfur-stabilizedanions Sulfonium salts Sulfoniumylids Sulfur-stabilizedcations Thiocarbonyl compounds Sulfoxides Other oxidations with sulfur and
selenium To conclude: the sulfur chemistry of onions and garlic Problems
47 Organo-main-group
chemistry 2: boron, silicon,
and tin
Organic chemists make extensiveuse of the periodic table Boron Silicon and carbon compared Organotin compounds Problems
48 Organometallic chemistry
Transition metals extend the range of organic reactions Transition metal complexes exhibit special bonding Palladium (0) is most widely usedin homogeneous catalysis Alkenes are attacked by nucleophiles when coordinated to palladium (11) Palladium catalysisin the total synthesis of a natural alkaloid Other transition metals: cobalt Problems
49 The chemistry of life
Primary metabolism Life begins with nucleic acids Proteins are made of amino acids Sugars-just energy sources? Glycosidesare everywhere in nature Compounds derived from sugars Most sugars are embedded in carbohydrates
23 Electrophilic alkenes Saccharin
Salbutamol Thyroxine
Introduction-electrophilic alkenes Nucleophilic conjugate addition to alkenes (^) Muscalure: the sex pheromone of the Conjugate substitution reactions house-fly Nucleophiiic epoxidation Nucleophiic aromatic substitution The addition-elimination mechanism
Grandisol: the sex pheromone of the male cotton boll weevil Peptide synthesis: carbonylchemistry in action The synthesis ofdofetilide, a drug to combat erratic heartbeat
Some medicinal chemistry-preparation of an antibiotic The SN1 mechanism for nucleophilic aromatic substitutiondiazonium compounds
Looking forward Problems The benzyne mechanism Nucleophilic attackon-allylic compounds To conclude... Problems
26 Alkylation of enolates
Carbonyl groups show diverse reactivity Some important considerations that affect all alkylations Nitriles and nitroalkanes can be alkylated Choice of electrophile for alkylation Lithium enolates of carbonyl compounds Alkylations of lithium enolates
24 Chemoselectivity:selective
reactions and protection
Selectivity Reducing agents Reduction of carbonyl groups Catalytic hydrogenation
Using specific en01equivalents to alkylate aldehydes and ketones Alkylation of P-dicarbonyl compounds Getting rid of functional groups (^) Ketone alkylation poses aproblem in Dissolving metal reductions regioselectivity One functional group may be more reactive than another for kineticor for thermodynamicreasons
Enones provide a solution to regioselectivityproblems To conclude... Problems Oxidizing agents To conclude... Problems
27 Reactions of enolates with
aldehydes and ketones:the
aldol reaction
Introduction: the aldol reaction
25 Synthesis in action
Introduction Benzocaine
Diazomethanemakes methyl esters from carboxylicacids Photolysis of diazomethane produces a carbene How are carbenes formed? Carbenes can be divided into two types How do carbenes react? Alkene (olefin)metathesis Summary Problems
41 Determining reaction
mechanisms 1079
There are mechanismsand there are mechanisms 1079 Determining reaction mechanisms- the Cannizzaro reaction 1081 Be sure ofthe structure ofthe product^1084 Systematicstructural variation 1089 The Hammett relationship 1090 Other kinetic evidence 1100 Acid and base catalysis 1102 The detection of intermediates 1109 Stereochemistryand mechanism 1113 Summary of methods for the investigation of mechanism 1117 Problems 1118
42 Saturated heterocycles and
stereoelectronics 1121
Introduction ZIII Reactions of heterocycles i l z z Conformation of saturated heterocycles: the anomeric effect 1128 Making heterocycles: ring-closing reactions 1134 Problems 1144
43 Aromatic heterocycles 1:
structures and reactions 1147
Introduction 1147 Aromaticiiy surviveswhen parts of benzene's ring are replaced by nitrogen atoms 1148 Pyridine is avery unreactive aromatic imine 1149 Six-membered aromatic heterocycles can have oxygen in the ring^1156 Five-memberedheterocycles are good nucleophiles 1157 Furan and thiophene are oxygen and sulfur analogues of pyrrole 1159 More reactions of five-membered heterocycles 1162 Five-memberedrings with two or more nitrogen atoms l l 6 5 Benzo-fused heterocycles 1169 Puttingmore nitrogen atoms in a six-memberedring 1172 Fusing rings to pyridines :quinolines andisoquinolines 1174 Heterocyclescan have many nitrogens but only one sulfur or oxygenin any ring 1176 There are thousands more heterocycles out there 1176 Which heterocyclic structures should you learn? 1180 Problems 1182
44 Aromatic heterocycles 2:
synthesis 1185
Thermodynamics is on our side 1185 Disconnect the carbon-heteroatom bonds first 1186 Pyrroles, thiophenes, and furans from 1,4-dicarbonylcompounds 1188 Howto make pyridines: the Hantzsch pyridine synthesis 1191 Pyrazoles and pyridazines from hydrazine
Lipids 1374 Bacteria and people have slightly different chemistry 1377 Problems 1379
50 Mechanisms in biological
chemistry 1381
Nature'sNaBH4 is anucleotide: NADH or NADPH 1381 Reductive amination in nature 1384 Nature's enols-lysine enamines and coenzymeA 1388 Nature's acyl anion equivalent (dl reagent) is thiamine pyrophosphate 1392 Rearrangements in the biosynthesis of valine and isoleucine 1397 Carbon dioxide is carried by biotin^1399 The shikimic acid pathway 1400 Haemoglobin carries oxygen as an iron(I1) complex 1406 Problems 1411
51 Natural products 1413
Introduction 1413 Natural products come from secondary metabolism 1414 Alkaloids are basic compounds from amino acid metabolism 1414 Fatty acids and other polyketides are made from acetyl CoA 1425 Aromatic polyketides come in great variety 1433 Terpenes are volatile constituents of plant resins and essential oils 1437
Steroids are metabolites of terpene origin 1441 Biomimetic synthesis: learning from Nature 1446 Problems 1447
52 Polymerization 1451
Monomers, dimers, and oligomers 1451 Polymerization by carbonyl substitution reactions 1453 Polymerization by electrophilicaromatic substitution 1455 Polymerization by the SN2 reaction 1456 Polymerization by nucleophilic attack on isocyanates 1458 Polymerization of alkenes 1459 Co-polymerization 1464 Cross-linkedpolymers 1466 Reactions of polymers 1468 Biodegradable polymers and plastics 1472 Chemical reagents can be bonded to polymers 1473 Problems 1478
53 Organic chemistrytoday 1481
Modern science is based on interaction between disciplines 1481 The synthesis of Crixivan 1483 The future of organic chemistry 1487
Index 1491
The organic compounds available to us today are those present in living things and those formed over millions of years from dead things. In earlier times, the organic compounds known from nature were those in the ‘essential oils’ that could be distilled from plants and the alkaloids that could be extracted from crushed plants with acid. Menthol is a famous example of a flavouring compound from the essential oil of spearmint and cis -jasmone an example of a perfume distilled from jasmine flowers.
Even in the sixteenth century one alkaloid was famous—quinine was extracted from the bark of the South American cinchona tree and used to treat fevers, especially malaria. The Jesuits who did this work (the remedy was known as ‘Jesuit’s bark’) did not of course know what the structure of quinine was, but now we do. The main reservoir of chemicals available to the nineteenth century chemists was coal. Distil- lation of coal to give gas for lighting and heating (mainly hydrogen and carbon monoxide) also gave a brown tar rich in aromatic compounds such as benzene, pyridine, phenol, aniline, and thiophene.
Phenol was used by Lister as an antiseptic in surgery and aniline became the basis for the dyestuffs industry. It was this that really started the search for new organic compounds made by chemists rather than by nature. A dyestuff of this kind—still available—is Bismarck Brown, which should tell you that much of this early work was done in Germany.
In the twentieth century oil overtook coal as the main source of bulk organic compounds so that simple hydrocarbons like methane (CH 4 , ‘natural gas’) and propane (CH 3 CH 2 CH 3 , ‘calor gas’) became available for fuel. At the same time chemists began the search for new molecules from new sources such as fungi, corals, and bacteria and two organic chemical industries developed in paral- lel—‘bulk’ and ‘fine’ chemicals. Bulk chemicals like paints and plastics are usually based on simple molecules produced in multitonne quantities while fine chemicals such as drugs, perfumes, and flavouring materials are produced in smaller quantities but much more profitably. At the time of writing there were about 16 million organic compounds known. How many more are possible? There is no limit (except the number of atoms in the universe). Imagine you’ve just made the longest hydrocarbon ever made—you just have to add another carbon atom and you’ve made another. This process can go on with any type of compound ad infinitum. But these millions of compounds are not just a long list of linear hydrocarbons; they embrace all kinds of molecules with amazingly varied properties. In this chapter we offer a selection.
2 1.^ What is organic chemistry?
L You will be able to read towards theend of the book (Chapters 49–51) about the extraordinary chemistry thatallows life to exist but this is known only from a modern cooperationbetween chemists and biologists.
L You can read about polymers andplastics in Chapter 52 and about fine chemicals throughout the book.
OH menthol
O
cis-jasmone
N
N
MeO
HO
quinine
benzene
N pyridine
OH
phenol
NH 2
aniline
S thiophene
N N^ N^ N
H 2 N NH 2 H 2 N NH 2
Bismarck Brown Y
CH 3 (CH 2 )n CH 2 CH 3 n = an enormous number length of molecule iscarbon atoms n + 3
CH 3 (CH 2 )n CH 3 n = an enormous numberlength of molecule isn + 2 carbon atoms
What do they look like? They may be crystalline solids, oils, waxes, plastics, elastics, mobile or volatile liquids, or gases. Familiar ones include white crystalline sugar, a cheap natural compound isolated from plants as hard white crystals when pure, and petrol, a mixture of colourless, volatile, flammable hydrocar- bons. Isooctane is a typical example and gives its name to the octane rating of petrol. The compounds need not lack colour. Indeed we can soon dream up a rainbow of organic compounds covering the whole spectrum, not to mention black and brown. In this table we have avoided dyestuffs and have chosen compounds as varied in struc- ture as possible.
Colour is not the only characteristic by which we recognize compounds. All too often it is their odour that lets us know they are around. There are some quite foul organic compounds too; the smell of the skunk is a mixture of two thiols—sulfur compounds containing SH groups.
Organic compounds 3
Colour Description Compound Structure red dark red hexagonal plates 3 ′-methoxybenzocycloheptatriene- 2 ′-one
orange amber needles dichloro dicyano quinone (DDQ)
yellow toxic yellow explosive gas diazomethane green green prisms with a 9-nitroso julolidine steel-blue lustre
blue deep blue liquid with a azulene peppery smell
purple deep blue gas condensing nitroso trifluoromethane to a purple solid
O
MeO
CH 2 N N N
NO
O
O
CN
Cl CN
Cl
C N O F
F F
s p e c t r u m
SH + SH
skunk spray contains:
volatile inflammable liquid white crystalline solid
O
O
HO
HO HO HO
O
OH
HO
HO OH CH 3 C^ C H 2
CH CH 3
CH CH^3 3
CH 3
sucrose – ordinary sugar isolated from sugar caneor sugar beet isooctane (2,3,5-trimethylpentane)a major constiuent of petrol
Don’t suppose that the females always do all the work; both male and female olive flies produce pheromones that attract the other sex. The remarkable thing is that one mirror image of the molecule attracts the males while the other attracts the females!
What about taste? Take the grapefruit. The main flavour comes from another sulfur compound and human beings can detect 2 × 10 –5^ parts per billion of this compound. This is an almost unimag- inably small amount equal to 10–4^ mg per tonne or a drop, not in a bucket, but in a good-sized lake. Why evolution should have left us abnormally sensitive to grapefruit, we leave you to imagine. For a nasty taste, we should mention ‘bittering agents’, put into dangerous household substances like toilet cleaner to stop children eating them by accident. Notice that this complex organic com- pound is actually a salt—it has positively charged nitrogen and negatively charged oxygen atoms— and this makes it soluble in water.
Other organic compounds have strange effects on humans. Various ‘drugs’ such as alcohol and cocaine are taken in various ways to make people temporarily happy. They have their dangers. Too much alcohol leads to a lot of misery and any cocaine at all may make you a slave for life. Again, let’s not forget other creatures. Cats seem to be able to go to sleep at any time and recently a compound was isolated from the cerebrospinal fluid of cats that makes them, or rats, or humans go off to sleep quickly. It is a surprisingly simple compound.
This compound and disparlure are both derivatives of fatty acids, molecules that feature in many of the food problems people are so interested in now (and rightly so). Fatty acids in the diet are a popular preoccupation and the good and bad qualities of satu- rates, monounsaturates, and polyunsaturates are continually in the news. This too is organic chemistry. One of the latest mole- cules to be recognized as an anticancer agent in our diet is CLA (conjugated linoleic acid) in dairy products.
Organic compounds 5
O
disparlure th h f th G th
disparlure the sex pheromone of the Gypsy mothPortheria dispar
O
O
olean sex pheromone of the olive flyBacrocera oleae
O O
O O
this mirror image isomer attracts the males this mirror image isomer attracts the females
HS
flavouring principle of grapefruit
H N N O
O
O
benzyldiethyl[(2,6-xylylcarbamoyl)methyl]ammonium benzoate denatonium benzoatebitrex
CH 3 OH (ethanol)^ alcohol CH^3 N
CO 2 Me O O cocaine
a sleep-inducing fatty acid derivative
O NH 2 cis-9,10-octadecenoamide
cis-9-trans-11 conjugated linoleic acid CLA (Conjugated Linoleic Acid)
O OH 18 10
9
11 1 12
dietary anticancer agent
Another fashionable molecule is resveratrole, which may be responsible for the beneficial effects of red wine in pre- venting heart disease. It is a quite different organic com- pound with two benzene rings and you can read about it in Chapter 51. For our third edible molecule we choose vitamin C. This is an essential factor in our diets—indeed, that is why it is called a vitamin. The disease scurvy, a degeneration of soft tissues, particularly in the mouth, from which sailors on long voyages like those of Columbus suffered, results if we don’t have vitamin C. It also is a universal antioxidant, scavenging for rogue free radicals and so protecting us against cancer. Some people think an extra large intake protects us against the common cold, but this is not yet proved.
Organic chemistry and industry
Vitamin C is manufactured on a huge scale by Roche, a Swiss company. All over the world there are chemistry-based companies making organic molecules on scales varying from a few kilograms to thousands of tonnes per year. This is good news for students of organic chemistry; there are lots of jobs around and it is an international job market. The scale of some of these operations of organic chemistry is almost incredible. The petrochemicals industry processes (and we use the products!) over 10 million litres of crude oil every day. Much of this is just burnt in vehicles as petrol or diesel, but some of it is purified or converted into organic compounds for use in the rest of the chemical industry. Multinational companies with thousands of employees such as Esso (Exxon) and Shell dominate this sector. Some simple compounds are made both from oil and from plants. The ethanol used as a starting material to make other compounds in industry is largely made by the catalytic hydration of ethylene from oil. But ethanol is also used as a fuel, particularly in Brazil where it is made by fermentation of sugar cane wastes. This fuel uses a waste product, saves on oil imports, and has improved the quality of the air in the very large Brazilian cities, Rio de Janeiro and São Paulo. Plastics and polymers take much of the production of the petro- chemical industry in the form of monomers such as styrene, acry- lates, and vinyl chloride. The products of this enormous industry are everything made of plastic including solid plastics for household goods and furniture, fibres for clothes (24 million tonnes per annum), elastic polymers for car tyres, light bubble-filled polymers for packing, and so on. Companies such as BASF, Dupont, Amoco, Monsanto, Laporte, Hoechst, and ICI are leaders here. Worldwide polymer production approaches 100 million tonnes per annum and PVC manufacture alone employs over 50 000 people to make over 20 million tonnes per annum. The washing-up bowl is plastic too but the detergent you put in it belongs to another branch of the chemical industry—companies like Unilever (Britain) or Procter and Gamble (USA) which produce soap, detergent, cleaners, bleaches, polishes, and all the many essentials for the modern home. These products may be lemon and lavender scented but they too mostly come from the oil industry. Nowadays, most pro- ducts of this kind tell us, after a fashion, what is in them. Try this example—a well known brand of shaving gel along with the list of contents on the container: Does any of this make any sense?
6 1.^ What is organic chemistry?
P Vitamin C (ascorbic acid) is a vitamin for primates, guinea-pigs, and fruit bats, but other mammals can make it for themselves.
which helps to prevent heart disease?^ is this the compound in red wine
OH
HO
OH
resveratrole from the skins of grapes
HO^ O
HO OH
O
OH H
vitamin C (ascorbic acid)
X O Cl
monomers for polymermanufacture
styrene
acrylates vinyl chloride
Ingredients aqua, palmitic acid, triethanolamine, glycereth-26, isopentane, oleamide-DEA, oleth-2, stearic acid, isobutane, PEG-14M, parfum, allantoin, hydroxyethyl-cellulose, hydroxypropyl-cellulose, PEG-150 distearate, CI 42053, CI 47005
