Question

Question: Assign E or Z configuration to each of the following compounds:

Short answer

Answer

1. Z configuration
2. Z configuration
3. E configuration
4. Z configuration

Step-by-step solution

Definition of E and Z configuration

When the substituents with highest priority on both carbon atom of alkene are present adjacent to each other, then the alkene has as Z configuration.

Similarly, when the highest priority groups are trans (opposite) to each other, then the alkene has E configuration.

Numbers 1 and 2 define the priority in the image given below here

Assigning configuration to (a)

Firstly priority needs to be assigned to both the groups on the two carbon atoms. The priority is decided on the basis of atomic number. The group with the highest atomic number will have the highest priority.

As similar priority groups are present on same sides, the molecule has Z configuration.

Assigning configuration to (b)

Firstly priority needs to be assigned to both the groups on the two carbon atoms. The priority is decided on the basis of atomic number. The group with the highest atomic number will have the highest priority.

As similar priority groups present on the same side, the molecule has Z configuration.

Assign configuration to (c)

Assign the priority on the basis of the atomic numbers of the different atoms which are attached to alkene.

As similar priority groups present on the same side. So, the configuration is E configuration

Assigning configuration to (d)

Assign the priority on the basis of the atomic numbers of the different atoms which are attached to alkene.

As similar priority groups present on the same side. So, the configuration is Z configuration.