Question

Which of the following structures of 1-methoxy-1, 3-butadiene is least stable?

• A.
• B.
• C.
• D.

Answer 1

The correct option is C

Rules for estimating stability of resonance structures

1. The greater the number of covalent bonds, the greater the stability since more atoms will have complete octets
2. The structure with the least number of formal charges is more stable
3. The structure with the least separation of formal charges is more stable
4. A structure with a negative charge on the more electronegative atom will be more stable
5. Positive charges on the least electronegative atom (most electropositive) is more stable
6. Resonance forms that are equivalent have no difference in stability and contribute equally.