Unlike palmerolide A (Problem 23.80), which has a large ring, a cyclic molecule with only six atoms can only have a cis double bond, but not a trans double bond. Give a line drawing of a cyclic molecule with six carbon atoms and a cis double bond. Explain why it cannot have a trans double bond.

Verified step by step guidance

1. Step 1: Begin by drawing a hexagonal ring to represent a cyclic molecule with six carbon atoms. This is known as cyclohexene when it contains a double bond.
2. Step 2: Identify the position where the double bond will be placed. In cyclohexene, the double bond is typically between two adjacent carbon atoms.
3. Step 3: Draw the double bond between two of the carbon atoms in the ring. Ensure that the remaining carbon atoms are single-bonded to each other to complete the hexagonal structure.
4. Step 4: Add hydrogen atoms to each carbon atom to satisfy the tetravalency of carbon. Each carbon should have a total of four bonds, including the bonds in the ring and the double bond.
5. Step 5: Explain why a trans double bond is not possible in a six-membered ring. A trans double bond would require the substituents on the double-bonded carbons to be on opposite sides, which would introduce significant ring strain due to the geometric constraints of a small ring, making it energetically unfavorable.