Question

Draw the structure for cis-2,3-dibromo-2-hexene.

Answer 1

Explanation:

Cis-2,3-dibromo-2-hexene has six carbon chain straight chain with double bond between second carbon and third carbon.

Cis-2,3 means that two bromine atoms bonded to the  second carbon and third carbon respectively on the same side of the double bond.

Refer to an image attached.

Answer 2

First, draw the 2-hexene. Th is is a molecule of six carbons with a double bond in the second carbon:

      CH3 - CH = CH2 - CH2 - CH2 - CH3

Secong, put one Br on the second carbon and one Br on the third carbon:

    CH3 - CBr = CBr - CH2 - CH2 - CH3

Third, cis means that the two Br are placed in opposed positions, this is drawn with one Br up and the other down. So, you need to represent the position of the Br in the space:


      H   Br          H     H      H
       |    |             |       |       |
H - C - C = C -  C  -  C  -  C - H
       |           |      |       |       |
      H          Br   H     H      H

The important fact to realize is that the two Br are in opposed sides of the molecule.