Question

Draw the following.

a. cis-2-hexene

b. trans-2-butene

c. cis-2,3-dichloro-2-pentene

Short answer

a.

b.

c.

Step-by-step solution

Definition of isomerism.

Isomerism refers to the presence of molecules with the same number of atoms of the same type (and hence the same formula) but different chemical and physical characteristics.

Subpart(a) The structure of cis-2-hexene.

• The longest chain is made up of six carbon atoms and therefore the root term is "hex."
• The prefixes "cis-"and "2-" indicate that this molecule is an isomer, with two bulky substituents on the same sideof the double bond.
• The suffix of the root "-ene" indicates that there is a carbon-carbon double bond.
• The structure for cis-2-hexene is shown below.

Subpart (b) The structure of trans-2-butene.

• The root word "but," shows that the longest chain has four carbon atoms.
• The suffix "-ene" indicates that there is a carbon-carbon double bond.
• The prefixes "trans-"and "2-" indicate that this compound is an isomercontaining two substituents on opposite sidesof the double bond.
• The structure for trans-2-butene is shown below.

Subpart (c) The structure of cis-2, 3-dichloro-2-pentene.

• The two bulky (higher priority-higher atomic mass) are on the same side of two double-bonded carbon atoms. Therefore, it is a cis isomer.
• Pen-2-enewith 5 carbons is drawn, and then both the chlorine atoms are positioned on the same side of the double bond.
• The structure for cis-2,3-dichloro-2-pentene is shown below.