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![Hydrocarbons
Mr.burhan Abdi
9
Hydrocarbons are compounds made up of only the
elements carbon and hydrogen.
They may be aliphatic or aromatic.
[1] Aliphatic hydrocarbons.
Aliphatic hydrocarbons can be divided into three subgroups.
Alkanes have only C – C σ bonds and no functional group.
Ethane, CH3CH3, is a simple alkane.
Alkenes have a C – C double bond as a functional group.
Ethylene, CH2––CH2, is a simple alkene.
Alkynes have a C – C triple bond as a functional group.
Acetylene, HC– CH, is a simple alkyne.
[2] Aromatic hydrocarbons.
This class of hydrocarbons was so named because many of the
earliest known aromatic compounds had strong, characteristic
odors.](https://image.slidesharecdn.com/nomenclatureoforganicchemistry-231218093540-524b4a26/75/nomenclature-of-organic-phychemistry-pptx-9-2048.jpg)
![Nomenclature of Carboxylic Acid
Mr.burhan Abdi
93
To name a carboxylic acid using the IUPAC
system:
[1] If the COOH is bonded to a chain of carbons, find
the longest chain containing the COOH group, and
Change the -e ending of the parent alkane to the suffix
-oic acid.
If the COOH group is bonded to a ring, name the ring and
add the words carboxylic acid.
[2] Number the carbon chain or ring to put the COOH
group at C1
Apply all of the other usual rules of
nomenclature.](https://image.slidesharecdn.com/nomenclatureoforganicchemistry-231218093540-524b4a26/75/nomenclature-of-organic-phychemistry-pptx-93-2048.jpg)
![Nomenclature of Aldehyde
Mr.burhan Abdi
98
To name an aldehyde using the IUPAC system:
[1] If the CHO is bonded to a chain of carbons, find
the longest chain containing the CHO group, and
change the -e ending of the parent alkane to the
suffix -al.
If the CHO group is bonded to a ring, name the ring
and add the suffix –carbaldehyde.
[2] Number the chain or ring to put the CHO group at
C1, but omit this number from the name.
Apply all of the other usual rules of
nomenclature.](https://image.slidesharecdn.com/nomenclatureoforganicchemistry-231218093540-524b4a26/75/nomenclature-of-organic-phychemistry-pptx-98-2048.jpg)
![Nomenclature of Ketone
Mr.burhan Abdi
101
In the IUPAC system all ketones are identified by the
suffix -one.
To name an acyclic ketone using IUPAC rules:
[1] Find the longest chain containing the carbonyl
group, and change the -e ending of the parent
alkane to the suffix –one.
[2] Number the carbon chain to give the carbonyl
carbon the lower number.
Apply all of the other usual rules of
nomenclature.](https://image.slidesharecdn.com/nomenclatureoforganicchemistry-231218093540-524b4a26/75/nomenclature-of-organic-phychemistry-pptx-101-2048.jpg)
![Mr.burhan Abdi
113
Polysubstituted Benzenes
For three or more substituents on a benzene
ring:
[1] Number to give the lowest possible numbers
around the ring.
[2] Alphabetize the substituent names.
[3] When substituents are part of common roots,
name the molecule as a derivative of that
monosubstituted benzene.
The substituent that comprises the common root is
located
at C1.](https://image.slidesharecdn.com/nomenclatureoforganicchemistry-231218093540-524b4a26/75/nomenclature-of-organic-phychemistry-pptx-113-2048.jpg)
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- 1.
- 2. Introduction to OrganicCompounds & Functional Groups Mr.burhan Abdi 2
- 3. Mr.burhan Abdi 3 Hydrocarbons (HC) aliphatic HC SaturatedHC alkanes Unsaturated HC alkenes alkynes Aromatic HC homocyclic heterocyclic
- 4. Mr.burhan Abdi 4 Classificationof organic compounds Aliphatic compounds These are open chain compounds These can be subdivided Saturated - alkanes Unsaturated – alkenes and alkynes Cyclic or closed chain compounds Cyclic compounds whose rings are made up of only one kind of atoms, i.e. carbon atoms are called homocyclic or cabocyclic compounds. Aliphatic cyclic compounds are called alicyclic compounds eg cyclopropane, cyclobutane etc
- 5. Mr.burhan Abdi 5 Organiccompounds containing one or more fused or isolated benzene rings and their functinalized derivatives are called benzenoids or aromatic compounds, eg benzene, toluene, naphthalene, anthracene etc. Cyclic compounds containing one or more heteroatoms (usually O,N, S etc) are called hetrocyclic compounds eg ethylene oxide, tetrahydrofuran (THF), furan, pyrole etc
- 6. Functional Groups Mr.burhan Abdi 6 Most organic molecules have C– C and C – H σ bonds. These bonds are strong, nonpolar, and not readily broken. Organic molecules may have the following structural features as well: Heteroatoms— Atoms other than carbon or hydrogen. Common heteroatoms are nitrogen, oxygen, sulfur, phosphorus, and the halogens. p Bonds. The most common π bonds occur in C – C and C – O double bonds.
- 7. Mr.burhan Abdi 7 FunctionalGroups These structural features distinguish one organic molecule from another. They determine a molecule’s geometry, physical properties, and reactivity Functional group is an atom or a group of atoms with characteristic chemical and physical properties. It is the reactive part of the molecule. A functional group determines all the following properties of a molecule: Type and strength of intermolecular forces Physical properties Nomenclature Chemical reactivity
- 8. An Overview ofFunctional Groups Mr.burhan Abdi 8 We can subdivide the most common functional groups into three types. Hydrocarbons Compounds containing a C – Z σ bond where Z = an electronegative element Compounds containing a C=O group A functional group is the structural unit responsible for a given molecule’s reactivity under a particular set of conditions.
- 9. Hydrocarbons Mr.burhan Abdi 9 Hydrocarbonsare compounds made up of only the elements carbon and hydrogen. They may be aliphatic or aromatic. [1] Aliphatic hydrocarbons. Aliphatic hydrocarbons can be divided into three subgroups. Alkanes have only C – C σ bonds and no functional group. Ethane, CH3CH3, is a simple alkane. Alkenes have a C – C double bond as a functional group. Ethylene, CH2––CH2, is a simple alkene. Alkynes have a C – C triple bond as a functional group. Acetylene, HC– CH, is a simple alkyne. [2] Aromatic hydrocarbons. This class of hydrocarbons was so named because many of the earliest known aromatic compounds had strong, characteristic odors.
- 10.
- 11. Compounds containing C–Zσ Bonds Mr.burhan Abdi 11 Several types of functional groups that contain C – Z bonds. The electronegative heteroatom Z creates a polar bond, making carbon electron deficient. The lone pairs on Z are available for reaction with protons and Other electrophiles, especially when Z = N or O.
- 12.
- 13. Compounds Containing aC=O Group Mr.burhan Abdi 13 Many different types of functional groups possess a C – O double bond (a carbonyl group) The polar C – O bond makes the carbonyl carbon an electrophile . While the lone pairs on O allow it to react as a nucleophile The carbonyl group also contains a π bond that is more easily broken than a C – O σ bond.
- 14.
- 15. Atenolol and Donepezilare examples of useful drugs that contain a variety of functional groups. Atenolol is a a blocker, a group of drugs used to treat hypertension. Donepezil is used to treat mild to moderate dementia associated with Alzheimer's disease. Mr.burhan Abdi 15
- 16. Assignment Mr.burhan Abdi 16 Oseltamivir(trade name Tamiflu), the most effective antiviral drug against avian influenza currently available, can be prepared in 10 steps from shikimic acid. Identify the functional groups in Tamiflu and shikimic acid.
- 17. Structural Formula Mr.burhan Abdi 17 Structural formula is a formula that shows how the atoms of a molecule are bonded to one another. Representation of structural formula Expanded Formula Condensed Formula Skeletal Formula 3-dimensional Formula Fisher Projection Formula
- 18. a) Expanded Structure Mr.burhanAbdi 18 Expanded structure indicate the way which the atoms are attached to each other and are not representation of the actual shapes of the molecules. Example : C4H10 Expanded structure
- 19. b) Condensed Formulae Mr.burhanAbdi 19 Condensed structures are most often used for compounds having a chain of atoms bonded together, rather than a ring The following conventions are used All of the atoms are drawn in, but the two-electron bond lines are generally omitted. Atoms are usually drawn next to the atoms to which they are bonded. Parentheses are used around similar groups bonded to the same atom. Lone pairs are omitted.
- 20. Mr.burhan Abdi 20 Remember It is usually best to start at the left side of the molecule The carbon atoms must be tetravalent.
- 21. c) Skeletal Structure Mr.burhanAbdi 21 Skeletal structures are used for organic compounds containing both rings and chains of atoms. Three important rules are used to draw them Assume there is a carbon atom at the junction of any two lines or at the end of any line. Assume there are enough hydrogens around each carbon to make it tetravalent. Draw in all heteroatoms and the hydrogens directly bonded to them. Other atoms such as O, Cl, N and etc are shown CH3CH(Cl)CH2CH3 = Cl
- 22. H2C CH2 H2C CH2 Mr.burhanAbdi 22 2. = CH2=CHCH2OH 3. = OH
- 23. Exercise Mr.burhan Abdi 23 Rewriteeach of the following structures using skeletal formula O CH3 CH2 CH2 C CH3 (CH3)2CHCH2CH2CH(CH3)CH2CH3 CH2= CHCH2CH2CH = CHCH3 O CH3 CH2 CH ( CH3 ) CH2 C OH 1. 2. 3. 4.
- 24. d) 3-Dimensional Formula Mr.burhanAbdi 24 Describes how the atoms of a molecule are arranged in space Example : C Br H H H (Bromoethane) C Br H H H C H Br H H C H H Br H Indication :- bonds that lie in the plane of the page bonds that lie behind the plane bonds that project out of the plane of the paper OR OR
- 25. e) Fischer Projection Mr.burhanAbdi 25 Vertical lines represent bonds that project behind the plane of the paper. Horizontal lines represent bonds that project out of the plane of paper The interaction of vertical and horizontal lines represent a carbon atom, that is stereocentre.
- 26. Example : 2– butanol , CH3CH(OH)CH2CH3 Mr.burhan Abdi 26 CH3 HO CH2 CH3 H CH3 H CH2 CH3 OH OR
- 27. Nomenclature of OrganicCompounds Mr.burhan Abdi 27
- 28. Introduction to Nomenclature Mr.burhanAbdi 28 How organic compounds named? Based on plant or animal source from which it was obtained With the isolation and preparation of thousands of new organic compounds it became clear that each organic compound must have an unambiguous name, derived from a set of easily remembered rules.
- 29. Mr.burhan Abdi 29 Asystematic method of naming compounds was developed by the International Union of Pure and Applied Chemistry (IUPAC) It is referred to as the IUPAC system of nomenclature The IUPAC system of nomenclature has been regularly revised since it was first adopted in 1892. Revisions in 1979 and 1993 and recent extensive recommendations in 2004 have given chemists a variety of acceptable names for compounds.
- 30. Mr.burhan Abdi 30 Namingorganic compounds has become big business for drug companies. The IUPAC name of an organic compound can be long and complex, and may be comprehensible only to a chemist. As a result, most drugs have three names: 1. Systematic name 2. Generic name 3. Trade name
- 31. Mr.burhan Abdi 31 Systematic: The systematic name follows the accepted rules of nomenclature and indicates the compound’s chemical structure; this is the IUPAC name. Generic: The generic name is the official, internationally approved name for the drug. Trade: The trade name for a drug is assigned by the company that manufactures it. Trade names are often “catchy” and easy to remember. Companies hope that the public will continue to purchase a drug with an easily recalled trade name long after a cheaper generic version becomes available.
- 32.
- 33. Introduction Mr.burhan Abdi 33 Alkanesare aliphatic hydrocarbons having only C–C and C – H σ bonds. They are also called saturated hydrocarbons because they have the maximum number of hydrogen atoms per carbon. Because their carbon atoms can be joined together in chains or rings, they can be categorized as acyclic or cyclic. Acyclic alkanes Cyclic alkanes
- 34. Mr.burhan Abdi 34 Acyclicalkanes Acyclic alkanes have the molecular formula CnH2n + 2 where n = an integer Contain only linear and branched chains of carbon atoms. Alkanes with C’s connected to no more than 2 other C’s are straight- chain or normal alkanes Alkanes with one or more C’s connected to 3 or 4 C’s are branched- chain alkanes
- 35.
- 36. Mr.burhan Abdi 36 Cycloalkanes Contain carbons joined in one or more rings. Because their general formula is CnH2n They have two fewer H atoms than an acyclic alkane with the same number of carbons. Simple cycloalkanes are named by adding the prefix cyclo- to the name of the acyclic alkane having the same number of carbons.
- 37. Types of Carbonand Hydrogen Atoms in Alkane Mr.burhan Abdi 37 Carbon atoms in alkanes and other organic compounds are classified by the number of other carbons directly bonded to them. A primary carbon (1° carbon ) is bonded to one other C atom. A secondary carbon (2° carbon) is bonded to two other C atoms A tertiary carbon (3° carbon) is bonded to three other C atoms. A quaternary carbon (4° carbon) is bonded to four other C atoms.
- 38.
- 39. Mr.burhan Abdi 39 Hydrogenatoms are classified as primary (1°), secondary (2°), or tertiary (3°) depending on the type of carbon atom to which they are bonded. A primary hydrogen (1° H) is on a C bonded to one other C atom. A secondary hydrogen (2° H) is on a C bonded to two other C atoms. A tertiary hydrogen (3° H) is on a C bonded to three other C atoms.
- 40.
- 41. Exercise Mr.burhan Abdi 41 Classifythe designated carbon atoms as 1°, 2°, 3°, or 4°. (b) Classify the designated hydrogen atoms as 1°, 2°, or 3°.
- 42. Assignment Mr.burhan Abdi 42 Classifythe carbon atoms in each compound as 1°, 2°, 3°, or 4°. Classify the hydrogen atoms in each compound as 1°, 2°, or 3°.
- 43. Naming Alkanes Mr.burhan Abdi 43 The name of every organic molecules have these parts Prefix - reveals the identity, location, and number of substituents attached to the carbon chain. Locant - gives the location of the primary functional group Parent name - indicates the number of carbons in the longest continuous carbon chain in the molecule. Suffix - indicates what functional group is present.
- 44. Mr.burhan Abdi 44 Followsspecific rules 1. Find parent hydrocarbon chain 2. Carbons in that main chain are numbered in sequence 3. Substituents are identified numbered 4. Write compound name is single word 5. Name a complex substituents as though it were a compound itself
- 45. Mr.burhan Abdi 45 Step1 Find the parent hydrocarbon Find the longest continuous chain of carbon atoms in the molecule, and use the name of that chain as the parent name. The longest chain may not always be apparent from the manner of writing; you may have to “turn corners.”
- 46. Mr.burhan Abdi 46 Iftwo different chains of equal length are present, choose the one with the larger number of branch points as the parent
- 47. Mr.burhan Abdi 47 Step2 Number the atoms in the main chain Beginning at the end nearer the first branch point, number each carbon atom in the parent chain.
- 48. Mr.burhan Abdi 48 Ifthere is branching an equal distance away from both ends of the parent chain, begin numbering at the end nearer the second branch point.
- 49. Mr.burhan Abdi 49 Step3 Identify the number of substituents Assign a number, called a locant, to each substituent to locate its point of attachment to the parent chain.
- 50. Mr.burhan Abdi 50 Ifthere are two substituents on the same carbon, give both the same number. There must be as many numbers in the name as there are substituents.
- 51. Mr.burhan Abdi 51 Step4 Write the name as a single word Use hyphens to separate the different prefixes, and use commas to separate numbers. If two or more different substituents are present, cite them in alphabetical order. If two or more identical substituents are present, use one of the multiplier prefixes di-, tri-, tetra-, and so forth, but don’t use these prefixes for alphabetizing. Full names for some of the examples we have been using follow.
- 52.
- 53.
- 54.
- 55. Mr.burhan Abdi 55 Step5 Name a complex substituent as though it were itself compound. In some particularly complex cases, a fifth step is necessary. It occasionally happens that a substituent on the main chain has sub-branching. In the following case, for instance, the substituent at C6 is a three-carbon chain with a methyl sub-branch. To name the compound fully, the complex substituent must first be named.
- 56. Mr.burhan Abdi 56 ConvertingIUPAC name into corresponding Structure 3-ethyl-4-methylhexane Steps Identify parent name and function group At end of the name – suffix Number the carbon skeleton in either direction Add the substituents at appropriate carbons
- 57. Mr.burhan Abdi 57 Givethe structure corresponding to each IUPAC name. 3-methylhexane 3,5,5-trimethyloctane 3,3-dimethylpentane
- 58. Naming of Cycloalkane Mr.burhanAbdi 58 Are cyclic alkanes. Have 2H fewer than the open chain. (CnH2n) Are named by using the prefix cyclo- before the name of the alkane chain with the same number of carbon atoms.
- 59. Mr.burhan Abdi 59 Cycloalkanesare named by using similar rules, but the prefix cyclo- immediately precedes the name of the parent.
- 60. Mr.burhan Abdi 60 Step1 Count the number of carbon atoms in the ring and use the parent name for that number of carbons. Add the prefix cyclo- and the suffix -ane to the parent name. Step2 Name and number the substituents. No number is needed to indicate the location of a single substituent.
- 61. Mr.burhan Abdi 61 Forrings with more than one substituent, begin numbering at one substituent and proceed around the ring clockwise or counterclockwise to give the second substituent the lower number.
- 62. Mr.burhan Abdi 62 Withtwo different substituents, number the ring to assign the lower number to the substituents alphabetically.
- 63. Class Activity Mr.burhan Abdi 63 Write the IUPAC name of the following compounds
- 64.
- 65.
- 66. Alkenes Mr.burhan Abdi 66 Alkenesare also called olefins. Alkenes are compounds that contain a carbon–carbon double bond. Terminal alkenes have the double bond at the end of the carbon chain Internal alkenes have at least one carbon atom bonded to each end of the double bond Cycloalkenes contain a double bond in a ring
- 67. Mr.burhan Abdi 67 Thedouble bond of an alkene consists of one σ bond and one π bond. The π bond is much weaker than the σ bond of a C – C double bond, making it much more easily broken. As a result, alkenes undergo many reactions that alkanes do not.
- 68. Nomenclature Mr.burhan Abdi 68 Alkenesare named using a series of rules similar to those for alkanes with the suffix -ene used instead of -ane to identify the family. Compounds with two double bonds are named as dienes by changing the -ane ending of the parent alkane to the suffix -adiene. Compounds with three double bonds are named as trienes, and so forth. Always choose the longest chain that contains both atoms of the double bond.
- 69.
- 70.
- 71.
- 72.
- 73. Mr.burhan Abdi 73 Alkynes,compounds that contain a carbon–carbon triple bond. Like alkenes, alkynes are nucleophiles with easily broken π bonds, and as such, they undergo addition reactions with electrophilic reagents.
- 74. Mr.burhan Abdi 74 Alkynescontain a carbon–carbon triple bond. A terminal alkyne has the triple bond at the end of the carbon chain, so that a hydrogen atom is directly bonded to a carbon atom of the triple bond. An internal alkyne has a carbon atom bonded to each carbon atom of the triple bond.
- 75. Mr.burhan Abdi 75 Analkyne has the general molecular formula CnH2n – 2, giving it four fewer hydrogens than the maximum number possible. Because every degree of unsaturation removes two hydrogens, a triple bond introduces two degrees of unsaturation. The triple bond of an alkyne consists of one σ bond and two π bonds.
- 76. Mr.burhan Abdi 76 Botho bonds of a C – C triple bond are weaker than a C – C r bond, making them much more easily broken. As a result, alkynes undergo many addition reactions. Alkynes are more polarizable than alkenes because the electrons in their o bonds are more loosely held.
- 77. Nomenclature Mr.burhan Abdi 77 Alkynesare named in the same way that alkenes were named. In the IUPAC system, change the -ane ending of the parent alkane to the suffi x –yne. Choose the longest carbon chain that contains both atoms of the triple bond and number the chain to give the triple bond the lower number. Compounds with two triple bonds are named as diynes, those with three are named as triynes, and so forth. Compounds with both a double and a triple bond are named as enynes. The chain is numbered to give the first site of unsaturation (either C – – C or C – – – C) the lower number.
- 78.
- 79.
- 80.
- 81. Structure Mr.burhan Abdi 81 Alkylhalides are organic molecules containing a halogen atom X bonded to carbon atom. The functional group is -X, where -X may be F, Cl, Br or I. Two simple members of this class are methyl chloride (CH3Cl) and ethyl chloride
- 82. Mr.burhan Abdi 82 Alkylhalides are classified as primary (1°), secondary (2°), or tertiary (3°) depending on the number of carbons bonded to the carbon with the halogen.
- 83. Nomenclature Mr.burhan Abdi 83 Analkyl halide is named as an alkane with a halogen substituent—that is, as a halo alkane. To name a halogen substituent, change the - ine ending of the name of the halogen to the suffix –o (chlorine → chloro).
- 84.
- 85.
- 86.
- 87. Structure Mr.burhan Abdi 87 Thefunctional group of an alcohol is the hydroxyl (- OH) group. Therefore, an alcohol has the general formula ROH. The simplest and most common alcohols are methyl alcohol (CH3OH) and ethyl alcohol (CH3CH2OH). When a hydroxyl group is linked directly to an aromatic ring, the compound is called a phenol
- 88. Mr.burhan Abdi 88 Alcoholsare classified as primary (1°), secondary (2°), or tertiary (3°) based on the number of carbon atoms bonded to the carbon with the OH group.
- 89.
- 90.
- 91.
- 92. Structure Mr.burhan Abdi 92 Carboxylicacids are organic compounds containing a carboxy group (COOH). The word carboxy (for a COOH group) is derived from carbonyl (C=O) + hydroxy (OH). Although the structure of a carboxylic acid is often abbreviated as RCOOH or RCO2H, keep in mind that the central carbon atom of the functional group is doubly bonded to one oxygen atom and singly bonded to another.
- 93. Nomenclature of CarboxylicAcid Mr.burhan Abdi 93 To name a carboxylic acid using the IUPAC system: [1] If the COOH is bonded to a chain of carbons, find the longest chain containing the COOH group, and Change the -e ending of the parent alkane to the suffix -oic acid. If the COOH group is bonded to a ring, name the ring and add the words carboxylic acid. [2] Number the carbon chain or ring to put the COOH group at C1 Apply all of the other usual rules of nomenclature.
- 94.
- 95.
- 96. Carbonyl – Aldehydeand Ketone Mr.burhan Abdi 96
- 97. Structure Mr.burhan Abdi 97 Aldehydesand ketones contain a carbonyl group. An aldehyde contains at least one H atom bonded to the carbonyl carbon. An aldehyde is often written as RCHO. Remember that the H atom is bonded to the carbon atom, not the oxygen. A ketone has two alkyl or aryl groups bonded to it. a ketone is written as RCOR, or if both alkyl groups are the same, R2CO.
- 98. Nomenclature of Aldehyde Mr.burhanAbdi 98 To name an aldehyde using the IUPAC system: [1] If the CHO is bonded to a chain of carbons, find the longest chain containing the CHO group, and change the -e ending of the parent alkane to the suffix -al. If the CHO group is bonded to a ring, name the ring and add the suffix –carbaldehyde. [2] Number the chain or ring to put the CHO group at C1, but omit this number from the name. Apply all of the other usual rules of nomenclature.
- 99.
- 100.
- 101. Nomenclature of Ketone Mr.burhanAbdi 101 In the IUPAC system all ketones are identified by the suffix -one. To name an acyclic ketone using IUPAC rules: [1] Find the longest chain containing the carbonyl group, and change the -e ending of the parent alkane to the suffix –one. [2] Number the carbon chain to give the carbonyl carbon the lower number. Apply all of the other usual rules of nomenclature.
- 102.
- 103.
- 104.
- 105. Introduction Mr.burhan Abdi 105 Inthe early days of organic chemistry, the word aromatic was used to describe such fragrant substances as benzaldehyde (from cherries, peaches, and almonds), toluene (from Tolu balsam), and benzene (from coal distillate). It was soon realized, however, that substances grouped as aromatic differed from most other organic compounds in their chemical behavior.
- 106. Mr.burhan Abdi 106 Today,we use the word aromatic to refer to the class of compounds that contain six-membered benzene- like rings with three double bonds. Many valuable compounds are aromatic in part, including steroids such as estrone and well-known pharmaceuticals such as the cholesterol-lowering drug atorvastatin, marketed as Lipitor.
- 107. Mr.burhan Abdi 107 Becausethese compounds possessed strong and characteristic odors, they were called aromatic compounds. It is their chemical properties, though, not their odor that make these compounds special. Aromatic compounds resemble benzene—they are unsaturated compounds that do not undergo the addition reactions characteristic of alkenes.
- 108. Nomenclature Mr.burhan Abdi 108 MonosubstitutedBenzenes To name a benzene ring with one substituent, name the substituent and add the word benzene. Carbon substituents are named as alkyl groups.
- 109. Mr.burhan Abdi 109 Manymonosubstituted benzenes, such as those with methyl (CH3 – ), hydroxy ( – OH), and amino ( – NH2) groups, have common names that you must learn, too.
- 110. Mr.burhan Abdi 110 DisubstitutedBenzenes There are three different ways that two groups can be attached to a benzene ring, so a prefix— ortho, meta, or para—can be used to designate the relative position of the two substituents. Ortho, meta, and para are also abbreviated as o, m, and p, respectively. – ortho- (o) on adjacent carbons (1,2) – meta- (m) separated by one carbon (1,3) – para- (p) separated by two carbons (1,4)
- 111.
- 112. Mr.burhan Abdi 112 Ifthe two groups on the benzene ring are different, alphabetize the names of the substituents preceding the word benzene. If one of the substituents is part of a common root, name the molecule as a derivative of that monosubstituted benzene.
- 113. Mr.burhan Abdi 113 PolysubstitutedBenzenes For three or more substituents on a benzene ring: [1] Number to give the lowest possible numbers around the ring. [2] Alphabetize the substituent names. [3] When substituents are part of common roots, name the molecule as a derivative of that monosubstituted benzene. The substituent that comprises the common root is located at C1.
- 114.
- 115. Mr.burhan Abdi 115 NamingAromatic Rings as Substituents A benzene substituent (C6H5 – ) is called a phenyl group, and it can be abbreviated in a structure as Ph – A phenyl group (C6H5 – ) is formed by removing one hydrogen from benzene (C6H6).
- 116. Mr.burhan Abdi 116 Benzene,therefore, can be represented as PhH, and phenol would be PhOH The benzyl group, another common substituent that contains a benzene ring, differs from a phenyl group.
- 117. Mr.burhan Abdi 117 Finally,substituents derived from other substituted aromatic rings are collectively called aryl groups.
- 118. Mr.burhan Abdi 118 Alkyl-substitutedbenzenes are sometimes referred to as arenes and are named in different ways depending on the size of the alkyl group. If the alkyl substituent is smaller than the ring (six or fewer carbons), the arene is named as an alkyl-substituted benzene. If the alkyl substituent is larger than the ring (seven or more carbons), the compound is named as a phenyl- substituted alkane.
- 119.
- 120.
- 121. Assignment Mr.burhan Abdi 121 Nomenclatureof polyfunctional organic compounds
- 122.
Editor's Notes
- #8 A functional group is the structural unit responsible for a given molecule’s reactivity under a particular set of conditions.
- #9 A functional group is the structural unit responsible for a given molecule’s reactivity under a particular set of conditions.
- #29 Formic acid formic acid, a caustic compound isolated from certain ants, comes from the Latin word formica, meaning ant; and allicin, the pungent principle of garlic, is derived from the botanical name for garlic, Allium sativum. Other compounds were named by their discoverer for more personal reasons. Adolf von Baeyer supposedly named barbituric acid after a woman named Barbara, although speculation continues on Barbara’s identity—a lover, a Munich waitress, or even St. Barbara.
- #94 In IUPAC nomenclature, carboxylic acids are identified by a suffix added to the parent name of the longest chain, and two different endings are used depending on whether the carboxy group is bonded to a chain or ring.