1. Chapter 11 Haloalkanes, Alkenes, and Alkynes
Geometric Isomers of Alkenes
Addition Reactions
Robert J. O'Reilly

2. Saturated and Unsaturated Compounds
Saturated compounds (alkanes) have the maximum number of hydrogen atoms attached to each carbon atom
Unsaturated compounds have fewer hydrogen atoms attached to the carbon chain than alkanes
Unsaturated compounds contain double or triple bonds
Robert J. O'Reilly

3. Alkenes Carbon-carbon double bonds Names end in -ene
H2C=CH2 ethene (ethylene)
H2C=CH-CH3 propene (propylene)
cyclohexene
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4. Alkynes Carbon-carbon triple bonds Names end in -yne
HCCH ethyne(acetylene)
HCC-CH3 propyne
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5. Naming Alkenes and Alkynes
When the carbon chain has 4 or more C atoms, number the chain to give the lowest number to the double or triple bond.
CH2=CHCH2CH3 1-butene
CH3CH=CHCH3 2-butene
CH3CHCHCH3 2-butyne
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6. Learning Check HA3
Write the IUPAC name for each of the following unsaturated compounds:
A. CH3CH2CCCH3
CH3
B. CH3C=CHCH3 C.
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7. Solutions HA3
Write the IUPAC name for each of the following unsaturated compounds:
A. CH3CH2CH=CHCH pentyne
CH3
B. CH3C=CHCH3 C.
2-methyl-2-butene methylcyclopentene
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8. Cis and Trans Isomers Double bond is fixed
Cis/trans Isomers are possible
CH3 CH CH3
CH = CH CH = CH
cis trans CH3
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9. Hydrogenation
Adds a hydrogen atom to each carbon atom of a double bond
H H H H Ni
H–C=C–H + H H–C–C–H
H H
ethene ethane
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10. Products of Hydrogenation
Adding H2 to vegetable oils produces compounds with higher melting points
Margarines
Soft margarines
Shortenings (solid)
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11. Learning Check HA4
What is the product of adding H2 (Ni catalyst) to 1-butene?
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12. Solution HA4
What is the product of adding H2 (Ni catalyst) to 1-butene? Ni
CH2=CHCH2CH3 + H2
CH3CH2CH2CH3
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13. Adding Halogens Halogens also add to the double bond of an alkene.
H2CCH Cl2
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14. Learning Check HA5
Write the product of the following addition reactions:
CH3CH=CHCH3 + H2
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15. Solution HA5 Write the product of the following addition reactions:
CH3CH=CHCH3 + H2 CH3CH2CH2CH3
Robert J. O'Reilly

16. Unsaturated Fatty Acids
Fatty acids in vegetable oils are omega-6 acids (the first double bond occurs at carbon 6 counting from the methyl group)
A common omega-6 acid is linoleic acid
CH3CH2CH2CH2CH2CH=CHCH2CH=CH(CH2)7COOH 6
linoleic acid, a fatty acid
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17. Trans Fats
In vegetable oils, the unsaturated fats usually contain cis double bonds.
During hydrogenation, some cis double bonds are converted to trans double bonds (more stable) causing a change in the fatty acid structure
If a label states “partially” or “fully hydrogenated”, the fats contain trans fatty acids.
Robert J. O'Reilly

18. Trans Fats
In the US, it is estimated that 2-4% of our total Calories is in the form of trans fatty acid.
trans fatty acids behave like saturated fatty acids in the body.
Several studies reported that trans fatty acids raise LDL-cholesterol. Some studies also report that trans fatty acid lower HDL-cholesterol
The trans fatty acids controversy will continue to be debated.
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19. Fats and Atheroschlerosis
Inuit people of Alaska have a high fat diet and high blood cholesterol levels, but a very low occurrence of atherosclerosis and heart attacks.
Fat in the Intuit diet was primarily from fish such as salmon, tuna and herring rather than from land animals (as in the American diet).
Robert J. O'Reilly

20. Omega-3 Fatty Acids
Fatty acids in the fish oils are mostly the omega-3 type (first double bond occurs at the third carbon counting from the methyl group).
linolenic acid 18 carbon atoms
CH3CH2CH=CHCH2CH=CHCH2CH=CH(CH2)7COOH 
eicosapentaenoic acid (EPA) 20 carbon atoms CH3CH2(CH=CHCH2)5(CH2)2COOH
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21. Atherosclerosis
Plaques of cholesterol adhere to the walls of the blood vessels
Blood pressure rises as blood squeezes through smaller blood vessels
Blood clots may form
Omega-3 fatty acids decrease the “sticking” of blood platelets (fewer blood clots)
Omega-3 fatty acids can increase bleeding time
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22. Learning Check HA6 (1) Ture or (2) False
A. ____ There are more unsaturated fats in vegetable oils.
B. ____ Vegetable oils have more omega-3 oils than found in fish.
C. ____ Hydrogenation of oils converts some cis-double bonds to trans- double bonds.
D. ____ Animal fats have more saturated fats.
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23. Solution HA6 (1) True or (2) False
A. _T__ There are more unsaturated fats in vegetable oils.
B. _F__ Vegetable oils have more omega-3 oils than found in fish.
C. _T__ Hydrogenation of oils converts some cis-double bonds to trans- double bonds.
D. _T__ Animal fats have more saturated fats.
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