The diagrams illustrate two different compounds. Determine: • the total number of structural isomers, including compound $2$, that could result from adding a second methyl group to the ring of compound $1$? • the number of $\pi$ electrons in each compound?
- Anumber of isomers $= 3$; number of $\pi$ electrons $= 2$
- Bnumber of isomers $= 3$; number of $\pi$ electrons $= 4$
- Cnumber of isomers $= 5$; number of $\pi$ electrons $= 2$
- Dnumber of isomers $= 5$; number of $\pi$ electrons $= 4$