Proloque Figure 1 a.Oral contraceptives c.Antibiotics Products of organi in me 78 b.Plastic syringes d.Synthetic heart valves .Organic chemistry has given us contraceptives,plastics,antibiotics,and the knitted material used in synthetic heart valves Some Representative Organic Molecules H other hydrocarbons-organic compounds that contain only carbon and hydrogen- methane that is,it burns in the presence of oxygen.Met hane is the produc re an Hydrocarbons such as methane are discussed in Chapter 4. HH Ethanol,the alcohol present in beer,wine,and other alcoholic beverages,is formed by the H- -OH ethanol
Some Representative Organic Molecules Perhaps the best way to appreciate the variety of organic molecules is to look at a few. Three simple organic compounds are methane, ethanol, and trichlorofl uoromethane. • Methane, the simplest of all organic compounds, contains one carbon atom. Methane—the main component of natural gas—occurs widely in nature. Like other hydrocarbons—organic compounds that contain only carbon and hydrogen— methane is combustible; that is, it burns in the presence of oxygen. Methane is the product of the anaerobic (without air) decomposition of organic matter by bacteria. The natural gas we use today was formed by the decomposition of organic material millions of years ago. Hydrocarbons such as methane are discussed in Chapter 4. • Ethanol, the alcohol present in beer, wine, and other alcoholic beverages, is formed by the fermentation of sugar, quite possibly the oldest example of organic synthesis. Ethanol can also be made in the lab by a totally different process, but the ethanol produced in the lab H H H H methane C H H H C H H OH ethanol C 2 Prologue Figure 1 Products of organic chemistry used in medicine • Organic chemistry has given us contraceptives, plastics, antibiotics, and the knitted material used in synthetic heart valves. a. Oral contraceptives c. Antibiotics b. Plastic syringes d. Synthetic heart valves smi75625_001-005prologue.indd 2 10/15/09 9:02:43 AM
Some Representative Organic Molecules 3 is identical to the ethanol produced by fermentation.Alcohols including ethanol are dis- cussed in Chapter 9. .Trichlorofluoromethane is a member of a class of molecules called chlorofluorocarbons or CFCs,which contain one or two carbon atoms and several halogens.Trichlorofluoro d trichlorofluoromethane an aerosol propellant and refrigerant.It and other CFCs have been implicated in the destruc tion of the stratospheric ozone layer,as is discussed in Chapter 15. plicated nd structures: .Each solid line represents a two-electron covalent bond. .When no atom is drawn at the corner of a ring,an organic chemist assumes it to be carbon For example.in the six-membered ring drawn.there is one carbon atom at each comer of the hexagon. two-electron bor A carbon atom is located at each comer. Three complex organic molecules that are important medications are amoxicillin,fluoxetine and AZT. fo fatal.You were likely gven som amoxicillin to treat an ear infe tion when you were a child.The penicillin antibiotics are discussed in Chapter22. H 的 HO- CH cafactories.Because it is safe and highly effective in treating depression.Prozac is widely prescribed.Over 40 million individuals worldwide have used Prozac since 1986. HH -CHCH2-N CH H
Some Representative Organic Molecules 3 is identical to the ethanol produced by fermentation. Alcohols including ethanol are discussed in Chapter 9. • Trichlorofl uoromethane is a member of a class of molecules called chlorofluorocarbons or CFCs, which contain one or two carbon atoms and several halogens. Trichlorofl uoromethane is an unusual organic molecule in that it contains no hydrogen atoms. Because it has a low molecular weight and is easily vaporized, trichlorofl uoromethane has been used as an aerosol propellant and refrigerant. It and other CFCs have been implicated in the destruction of the stratospheric ozone layer, as is discussed in Chapter 15. Because more complicated organic compounds contain many carbon atoms, organic chemists have devised a shorthand to draw them. Keep in mind the following when examining these structures: • Each solid line represents a two-electron covalent bond. • When no atom is drawn at the corner of a ring, an organic chemist assumes it to be carbon. For example, in the six-membered ring drawn, there is one carbon atom at each corner of the hexagon. H H H H H H C C C C C C H H H H H H = a two-electron bond A carbon atom is located at each corner. Three complex organic molecules that are important medications are amoxicillin, fl uoxetine, and AZT. • Amoxicillin is one of the most widely used antibiotics in the penicillin family. The discovery and synthesis of such antibiotics in the twentieth century have made routine the treatment of infections that were formerly fatal. You were likely given some amoxicillin to treat an ear infection when you were a child. The penicillin antibiotics are discussed in Chapter 22. N S O H H CH3 CH3 H C HO O C O C H NH2 HO H amoxicillin H H H H N • Fluoxetine is the generic name for the antidepressant Prozac. Prozac was designed and synthesized by chemists in the laboratory, and is now produced on a large scale in chemical factories. Because it is safe and highly effective in treating depression, Prozac is widely prescribed. Over 40 million individuals worldwide have used Prozac since 1986. O H H H H H H fluoxetine CH2CH2 N CH3 H CF3 C H H H H Cl C Cl F Cl trichlorofluoromethane smi75625_001-005prologue.indd 3 10/15/09 9:02:47 AM
Prologue ch H 0=〈 HO Other complex oranic compounds having interesting properties are capsaicin and DDT. Capsaicin,one member of a group of compounds called vanilloids,is responsible for the characteristic spiciness of hot peppers.It is the active ingredient in pepper sprays used for personal defense and topical creams used for pain reliet 烂g"以o capsaicin DDT,the abbreviation for dichlorodiphenyltrichloroethane.is a pesticide once called iraculous by use is now banned in the United States and many developed DDT What are the common features of these organic compounds? tom is said to alent. called a .Some compounds have chains of atoms and some compounds have rings These features explain why there are so many organic compounds:Carbon forms four strong bonds with itself and other elements.Carbon atoms combine together to form rings and chains Ginkgolide B-A Complex Organic Compound from the Ginkgo Tree Let's complete this discussion with ginkgolide B(CH,O),a complex organic compound isolated from the ginkgo tree Ginko biloba.the oldest seed-producing plant that currently lives on earth(Figure ir tree.Ginkgo ooa nas existea for over 280 m from the ots bark.ed have been used in chines
O C N3 H H H H N H N O O CH3 H HO H H AZT H Other complex organic compounds having interesting properties are capsaicin and DDT. • Capsaicin, one member of a group of compounds called vanilloids, is responsible for the characteristic spiciness of hot peppers. It is the active ingredient in pepper sprays used for personal defense and topical creams used for pain relief. capsaicin CH3O HO C N H C O C C C C C C C CH3 H H H CH3 H H H H H H H H H H H H H • DDT, the abbreviation for dichlorodiphenyltrichloroethane, is a pesticide once called “miraculous” by Winston Churchill because of the many lives it saved by killing diseasecarrying mosquitoes. DDT use is now banned in the United States and many developed countries because it is a nonspecifi c insecticide that persists in the environment. C CCl3 H HH Cl H H HH H H Cl DDT What are the common features of these organic compounds? • All organic compounds contain carbon atoms and most contain hydrogen atoms. • All the carbon atoms have four bonds. A stable carbon atom is said to be tetravalent. • Other elements may also be present. Any atom that is not carbon or hydrogen is called a heteroatom. Common heteroatoms include N, O, S, P, and the halogens. • Some compounds have chains of atoms and some compounds have rings. These features explain why there are so many organic compounds: Carbon forms four strong bonds with itself and other elements. Carbon atoms combine together to form rings and chains. Ginkgolide B—A Complex Organic Compound from the Ginkgo Tree Let’s complete this discussion with ginkgolide B (C20H24O10), a complex organic compound isolated from the ginkgo tree Ginkgo biloba, the oldest seed-producing plant that currently lives on earth (Figure 2). Also called the maidenhair tree, Ginkgo biloba has existed for over 280 million years, and fossil records indicate that it has undergone little signifi cant evolutionary change for eons. Extracts from the roots, bark, leaves, and seeds have been used in traditional Chinese • AZT, the abbreviation for azidodeoxythymidine, is a drug that treats human immuno defi ciency virus (HIV), the virus that causes acquired immune defi ciency syndrome (AIDS). Also known by its generic name zidovudine, AZT represents a chemical success to a different challenge: synthesizing agents that combat viral infections. 4 Prologue smi75625_001-005prologue.indd 4 10/15/09 9:02:47 AM
Ginkgolide B-A Complex Organic Compound from the Ginkgo Tree inkgolide B ”icgneeenigotgeaboasaeomiednhestctureodgnkgoiaeB,aconvenmio medicine t rise th nost widel and treat dementia.Recent findings of the National Institutes of Health,however,have cast doubt on its efficacy in providing any long-term improvement in cognitive function. three-dimensional shape made it a challenging molecule to prepare in the laboratory.Professo rat avad University epred the synthesis of ginkgolide B in the In this introduction.we have seen a variety of molecules that have dive resent a miniscule fraction of the organic compounds currently known and the many thousands that are newly discovered or synthesized each year.The principles you learn in organic chemistry app to all。 ese m tions that we will study in organic chemistry. WELCOME TO THE WORLD OF ORGANIC CHEMISTRY!
Ginkgolide B—A Complex Organic Compound from the Ginkgo Tree 5 medicine to treat asthma and improve blood circulation. Today, ginkgo extracts comprise the most widely taken herbal supplements, used by some individuals to enhance memory and treat dementia. Recent fi ndings of the National Institutes of Health, however, have cast doubt on its effi cacy in providing any long-term improvement in cognitive function. In 1932 ginkgolide B was one of four components isolated from ginkgo extracts, and its structure was determined in 1967. Although its rigid ring system of 20 carbons contained in a compact three-dimensional shape made it a challenging molecule to prepare in the laboratory, Professor E. J. Corey and co-workers at Harvard University reported the synthesis of ginkgolide B in the laboratory in 1988. In this introduction, we have seen a variety of molecules that have diverse structures. They represent a miniscule fraction of the organic compounds currently known and the many thousands that are newly discovered or synthesized each year. The principles you learn in organic chemistry will apply to all of these molecules, from simple ones like methane and ethanol, to complex ones like capsaicin and ginkgolide B. It is these beautiful molecules, their properties, and their reactions that we will study in organic chemistry. WELCOME TO THE WORLD OF ORGANIC CHEMISTRY! O O O ginkgolide B O O CH3 C(CH3)3 OH OH HO O O Figure 2 Ginkgolide B • Hydrogen atoms bonded to ring carbons are omitted in the structure of ginkgolide B, a convention described in Section 1.7. smi75625_001-005prologue.indd 5 10/15/09 9:02:47 AM
Structure and Bonding 1.1 The 1.3 Lewding 1.4 Lewis structures 1.Determining molec 1.7 shape ene.an 1.11 Elect ativity and 1.12 Pola 1.13 L-Dop ntative has b en the ug ot choi on's disease,a mine in the brain.Dopa is an oral medication that is trar orted to the brain by en in large dose mpact on an indi e L-dopa
Structure and Bonding L-Dopa, also called levodopa, was fi rst isolated from seeds of the broad bean plant Vicia faba in 1913. Since 1967 it has been the drug of choice for the treatment of Parkinson’s disease, a debilitating illness that results from the degeneration of neurons that produce the neurotransmitter dopamine in the brain. L-Dopa is an oral medication that is transported to the brain by the bloodstream, where it is converted to dopamine. Since L-dopa must be taken in large doses with some serious side effects, today it is often given with other drugs that lessen its negative impact on an individual. In Chapter 1, we learn about the structure, bonding, and properties of organic molecules like L-dopa. 1.1 The periodic table 1.2 Bonding 1.3 Lewis structures 1.4 Lewis structures continued 1.5 Resonance 1.6 Determining molecular shape 1.7 Drawing organic structures 1.8 Hybridization 1.9 Ethane, ethylene, and acetylene 1.10 Bond length and bond strength 1.11 Electronegativity and bond polarity 1.12 Polarity of molecules 1.13 L-Dopa—A representative organic molecule 1 6 smi75625_006-053ch01.indd 6 10/15/09 9:58:18 AM