alkenes and alkynes 1 alkenes and alkynes are two families of organic molecules that contain...
TRANSCRIPT
![Page 1: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/1.jpg)
Alkenes and Alkynes
1
Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated).
• Alkenes are compounds that contain a carbon− carbon double bond.
• Alkenes have the general formula CnH2n.
![Page 2: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/2.jpg)
Alkenes and Alkynes
2
• Alkynes are compounds that contain a carbon− carbon triple bond.
• Alkynes have the general formula CnH2n–2.
![Page 3: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/3.jpg)
Alkenes and Alkynes
3
• Alkenes and alkynes have low melting and boiling points, and are insoluble in water.
• Alkenes and alkynes are composed of nonpolar bonds.
• Their physical properties are like those of alkanes.
• They are called unsaturated hydrocarbons because they contain fewer than the maximum number of H atoms per C.
![Page 4: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/4.jpg)
Alkenes and Alkynes
4
• The multiple bond is always drawn in a condensed structure.
• An alkene is identified by the suffix – ene.
• An alkyne is identified by the suffix – yne.
![Page 5: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/5.jpg)
Nomenclature of Alkenes and Alkynes
5
HOW TO Name an Alkene or Alkyne
ExampleGive the IUPAC name of each alkene and alkyne.
Step [1] Find the longest chain that contains bothC atoms of the double or triple bond.
![Page 6: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/6.jpg)
Nomenclature of Alkenes and Alkynes
6
HOW TO Name an Alkene or Alkyne
4 C’s in longest chain
• Since the compound is an alkene, change the −ane ending to −ene.
butane ----> butene
6 C’s in longest chainhexane ----> hexyne
• Since the compound is an alkyne, change the −ane ending to −yne.
![Page 7: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/7.jpg)
Nomenclature of Alkenes and Alkynes
7
HOW TO Name an Alkene or Alkyne
Step [2]Number the carbon chain from the end thatgives the multiple bond the lower number.
• Name the compound using the first number assigned to the multiple bond.
1-butene 2-hexyne
![Page 8: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/8.jpg)
8
Nomenclature of Alkenes and Alkynes
HOW TO Name an Alkene or Alkyne
Step [3]
Number and name the substituents, and write the name.
![Page 9: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/9.jpg)
9
Cis–Trans IsomersStereoisomers—A New Class of Isomer
• There is restricted rotation around the C atoms of a double bond.
two CH3 groupson the same side
two CH3 groupson opposite sides
• Therefore, 2-butene has two possible arrangements:
cis isomer trans isomer
![Page 10: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/10.jpg)
Cis–Trans IsomersStereoisomers—A New Class of Isomer
10
![Page 11: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/11.jpg)
Cis–Trans IsomersStereoisomers—A New Class of Isomer
11
• Whenever the two groups on each end of a C═C are different from each other, two isomers are possible.
![Page 12: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/12.jpg)
Cis–Trans IsomersStereoisomers—A New Class of Isomer
12
• When the two groups on one end of the double bond are identical (e.g., both H or both CH3), no cis and trans isomers are possible.
![Page 13: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/13.jpg)
Cis–Trans IsomersStereoisomers—A New Class of Isomer
13
• Stereoisomers are isomers that differ only in the 3-D arrangement of atoms.
• Constitutional isomers differ in the way the atoms are bonded to each other.
![Page 14: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/14.jpg)
Focus on Health and MedicineSaturated and Unsaturated Fatty Acids
14
• Fatty acids are carboxylic acids (RCOOH) with long carbon chains of 12–20 carbon atoms.
• Naturally occurring animal fats and vegetable oils are formed from fatty acids.
• Saturated fatty acids have no double bonds in their long hydrocarbon chains.
• Unsaturated fatty acids have one or more double bonds in their long hydrocarbon chains.
![Page 15: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/15.jpg)
Focus on Health and MedicineSaturated and Unsaturated Fatty Acids
15
![Page 16: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/16.jpg)
Reactions of Alkenes
16
Alkenes undergo addition reactions wherein newgroups X and Y are added to the alkene. One bondof the double bond is broken and two new singlebonds are formed.
![Page 17: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/17.jpg)
Reactions of AlkenesAddition of Hydrogen—Hydrogenation
17
• Hydrogenation is the addition of H2 to an alkene.
• The metal catalyst (usually palladium—Pd) speeds up the rate of the reaction.
• The product of hydrogenation is an alkane.
![Page 18: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/18.jpg)
Reactions of AlkenesAddition of Hydrogen—Hydrogenation
18
• Another example of hydrogenation:
![Page 19: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/19.jpg)
Reactions of alkenesAddition of halogens-Halogenation
1,2-Dichloroethane
Results in the formation of haloalkanes.
19
C C
H
H
H
H
+ Cl Cl C C
H
H
H
H
ClCl
![Page 20: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/20.jpg)
20
Reactions of AlkenesAddition of Water—Hydration
• Hydration is the addition of water to an alkene.
• Hydration requires a strong acid, H2SO4.
• The product formed by hydration is an alcohol.
![Page 21: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/21.jpg)
21
Reactions of AlkenesAddition of Water—Hydration
• An additional example of hydration:
![Page 22: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/22.jpg)
22
•If the reactant is an asymmetrical alkene, two possible products can be formed in theory.
•These two potential products are constitutional isomers. In fact, addition only forms 2-propanol.
Reactions of AlkenesAddition of Water—Hydration
![Page 23: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/23.jpg)
23
•To determine which of the two products will actually form, we use Markovnikov’s rule.
•Markovnikov’s rule states that the H atom of H–OH will bond to the less substituted C atom in the C═C double bond.
•This means the C in the double bond with the most Hs will bond to the H atom of H–OH.
Reactions of AlkenesAddition of Water—Hydration
![Page 24: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/24.jpg)
24
•Looking at the reaction again:
C2 is bonded to 1 HC1 is bonded to 2 Hs
•C1 has more Hs, so it will bond to the H from H–OH.
•2-propanol is the only product formed.
Reactions of AlkenesAddition of Water—Hydration
![Page 25: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/25.jpg)
25
Focus on Health and MedicineMargarine or Butter?
![Page 26: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/26.jpg)
Alkene Polymers-(Polymerization)
.
Polystyrene (plastic/foam cups)
C C
H
H
Cl
H
+ C C
H
H
Cl
H
+ C C
H
H
Cl
H
C C
H
H
Cl
H
C C
H
H
Cl
H
C
H
H
C
Cl
H
Monomer (n = Polymer (n up to 2 ) 1000 and more)
Chloroethene
(Vinyl chloride)
Polyvinyl Chloride
H2C C
H
???
Phenylethene
(Styrene)
Polystyrene
![Page 27: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/27.jpg)
27
Polymers—The Fabric of Modern Society
• Polymers are large molecules made up of repeating units of smaller molecules (monomers) covalently bonded together.
![Page 28: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/28.jpg)
28
Polymers—The Fabric of Modern SocietySynthetic Polymers
• In polymerization, the weak bond that joins the two carbons of the double bond is broken and new strong carbon–carbon single bonds join the monomers together.
![Page 29: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/29.jpg)
29
Polymers—The Fabric of Modern SocietySynthetic Polymers
![Page 30: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/30.jpg)
30
Aromatic Compounds
• Aromatic compounds are compounds that contain a benzene ring.
• Each C is trigonal planar (i.e., 120°bond angles), making benzene a planar molecule.
![Page 31: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/31.jpg)
31
Aromatic Compounds
• Each of these representations has the same arrangement of atoms, but different locations of electrons.
• Each of these representations is equivalent.
• The physical properties of aromatic hydrocarbons are similar to other hydrocarbons—they have low melting points and boiling points and are water insoluble.
![Page 32: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/32.jpg)
32
• Tamoxifen, a potent anticancer drug sold under the trade name Novaldex, contains three benzene rings.
Aromatic Compounds
![Page 33: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/33.jpg)
33
Nomenclature of Benzene DerivativesMonosubstituted Benzenes
To name a benzene ring with one substituent:
• name the substituent first
• then add the word benzene at the end.
![Page 34: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/34.jpg)
34
Nomenclature of Benzene DerivativesMonosubstituted Benzenes
• Some monosubstituted benzenes have common names that you must learn.
![Page 35: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/35.jpg)
35
Nomenclature of Benzene DerivativesDisubstituted Benzenes
![Page 36: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/36.jpg)
36
Nomenclature of Benzene DerivativesDisubstituted Benzenes
• If there are two groups on the benzene ring and they are different, alphabetize the two substituent
names.
![Page 37: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/37.jpg)
37
Nomenclature of Benzene DerivativesDisubstituted Benzenes
• If one of the two substituents is part of a common root, then name the molecule as a derivative of that monosubstituted benzene.
![Page 38: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/38.jpg)
38
Nomenclature of Benzene DerivativesPolysubstituted Benzenes
1. Number to give the lowest possible numbers around the ring.
2. Alphabetize the substituent names.
3. When the substituents are part of common roots:
• Put the common root substituent at C1, but omit the “1” from the name.
• Name the molecule as a derivative of that monosubstituted benzene.
![Page 39: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/39.jpg)
39
Nomenclature of Benzene DerivativesPolysubstituted Benzenes
• Assign the lowest set of numbers.
• Alphabetize the names of all the substituents.
1-chloro-4-ethyl-3-propylbenzene
CH2CH3
CH2CH2CH3Cl
4
31
![Page 40: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/40.jpg)
40
Nomenclature of Benzene DerivativesPolysubstituted Benzenes
• Name the molecule as a derivative of the common root aniline.
• Assign the NH2 group to position 1, then assign the lowest possible set of numbers to the other groups.
2,5-dichloroaniline
![Page 41: Alkenes and Alkynes 1 Alkenes and alkynes are two families of organic molecules that contain multiple bonds (unsaturated). Alkenes are compounds that contain](https://reader031.vdocuments.us/reader031/viewer/2022032016/56649e5f5503460f94b58b41/html5/thumbnails/41.jpg)
41
Focus on Health and MedicineSunscreens and Antioxidants
• A common sunscreen used contains benzene:
• A wide variety of phenols occur in nature: