1. Draw the following 2-pentene 5,6-dimethyloct-3-en-1-yne
2,3,3-trimethylbut-1-ene
2-chloro-2-methylpropane
If done correctly, they should match some of the odd numbers on the HW packet

2. Check your evens
Alkene 2. Prop-1-ene 4. 3-sec-butyl-2-methylhept-2-ene 6. Hex-3-ene 8. 4-methylpent-2-ene ethyl-4,6-dimethyloct-2-ene 4. Hept-3-ene
Alkyne
2. but-2-yne
4. non-4-yne
6. 5-ethyl-5-methyloct-3-yne
8. pent-3-en-1-yne
10. hept-3-en-1-yne

3. Check your odds
Alkene 1. ethene 3. pent-2-ene 5. 3-sec-butyl-2-methylhept-2-ene 7. 5-isopropyloct-3-ene 9. 2,3,3-trimethylbut-1-ene 3. 1-butene 5. 4-methylhex-2-ene
Alkyne
1. but-1-yne
3. prop-1-yne
5. 5,5-dimethylhex-1-yne
7. 3-methyl-oct-1,4-diyne
9. oct-5-en-2-yne
11. 5,6-dimethyloct-3-en-1-yne

4. Cycloalkanes Cyclopropane C3H6
Draw #6 1-ethyl-2,5-dimethylcycloheptane
#8, 3, 13

5. Learning Check
Write the IUPAC name for each of the following unsaturated compounds:
A. CH3CH2CCCH3
CH3
B. CH3C=CHCH3 C.

6. Aromatic Compounds and the Structure of Benzene
In the early days the word aromatics was used to described many fragrant molecules isolated from natural sources.
Today the term aromatic is used to describe benzene like molecules.
Benzene is a flat, symmetrical molecule with the molecular formula C6H6.
It has alternating three carbon-carbon double and three single bonds.

7. Aromatic Compounds and Benzene
Aromatic compounds contain benzene.
Benzene, C6H6 , is represented as a six carbon ring with 3 double bonds.
Two possible can be drawn to show benzene in this form.

8. Benzene’s relatively lack of chemical reactivity is due to its structure.
There are two possible structures with alternating double and single bonds.

9. The properties of benzene can only be explained by assuming that the actual structure of benzene is an average of the above two possible equivalent structures-known as resonance.
Simple aromatic compounds like benzene are non-polar, insoluble in water, volatile, and flammable.

10. Aromatic Compounds in Nature and Health
Many aromatic compounds are common in nature and in medicine.

11. Naming Aromatic Compounds
Aromatic compounds are named with benzene as the parent chain. One side group is named in front of the name benzene.
- No number is needed for mono-substituted benzene since all the ring positions are identical.
methylbenzene chlorobenzene
(toluene)

12. Naming Aromatic Compounds
When two groups are attached to benzene, the ring is numbered to give the lower numbers to the side groups. The prefixes ortho (1,2), meta (1,3-) and para (1,4-) are also used.

13. Some Common Names
Some substituted benzene rings also use a common name. Then naming with additional more side groups uses the ortho-, meta-, para- system.

14. Many substituted aromatic compounds have common names in addition to their systematic names.

15. Learning Check Select the names for each structure:
a. Chlorocyclohexane
b. Chlorobenzene
c. 1-chlorobenzene
a. Meta-xylene
b. Meta-dimethylbenzene
c. 1,3-dimethylbenzene

16. Learning Check
Write the structural formulas for each of the following:
A. 1,3-dichlorobenzene
B. Ortho-chlorotoluene OR 2-chlorotoluene

19. Functional Group
Ending
alkane
ane
alkene
ene
alkyne
yne
alcohol ol
ketone
one
aldehyde al
carboxylic acid
oic acid
ester
oate
amide