What are the isomers of witches

Example: C4H8 Butene

- Constitutional isomers: each different arrangement of atoms and bonds

    1-butene (outdated: 1-butene)

The constitution indicates how the atoms are linked to one another in a compound.

- Cis/trans-Isomers: same constitution (bonds) but different configurations
    cis-But-2-en (outdated: cis-2-butene)
(Z) -But-2-en (obsolete: (Z) -2-butene)
trans-But-2-en (outdated: trans-2-butene)
(E.) -But-2-en (obsolete: (E.) -2-butene)

Cis-trans isomers have the same constitution (the links are identical), but they differ in their configuration (the spatial arrangement of their atoms).

2 double bonds:


3 double bonds:


multiple double bonds:


- isolated double bonds
CH2= CH-CH2-CH2-CH = CH-CH3 Hepta-1,5-diene (outdated: 1,5-heptadiene)
There are several single bonds between the 2 double bonds.

- conjugated double bonds
CH2= CH-CH = CH-CH2-CH2-CH3 Hepta-1,3-diene (outdated: 1,3-heptadiene)
There is 1 single bond between the 2 double bonds.

- accumulated double bonds
CH3-CH = C = CH-CH3 Penta-2,3-diene (outdated: 2,3-pentadiene)
2 double bonds emanate from 1 carbon atom

1. Exercise 2, page 292
Formulate the semi-structural formulas of cis-2-witches and from trans-2 witches.

2. Exercise 1, page 292
Formulate the semi-structural formulas of six alkene isomers of the pentene molecule and name them unambiguously.

3. Exercise 3, page 292
Formulate the semi-structural formulas of:

1,3-butadiene 2-methyl-1,3-butadiene 2-chloro-1,3-butadiene

4. Exercise 2, page 296
a. Enter the following semi-structural formulas:
• 3,4-dimethylhexane

• 4-ethyl-2,4-dimethylheptane

• 2-chloro-2-methylbutane

b. Name the following molecules:

5. Exercise 7 on page 296
Formulate the semi-structural formulas for the following compounds:
4-ethyl-2,3-dimethyl-2-hexene     4-bromo-1-pentene

3-bromo-2,4-dimethyl-1,3-pentadiene 3-ethyl-1-hexene

6. Exercise 12 on page 296
Explain the following: Compared to the addition to ethene, the addition of bromine to 2,3-dimethyl-2-butene is about 15 times faster, the addition to 1,2-dichloroethene about 50 times slower.

7. Give the empirical formula for the higher homologue of heptane and give the semi-structural formulas and names of two isomers of this higher homologue which have at least 2 branches.

8. An unsaturated hydrocarbon (M = 110 g / mol) has two double bonds. Draw up the general molecular formula for such hydrocarbons and use this formula to calculate the chemical formula.