organic chemistry\nrecognizing different skeletal structures\nhow many different molecules are drawn below?

Answer

Explanation:

Step1: Analyze the first molecule

The first molecule (top left) is (E)-3,4-dimethylpent-2-ene. The isopropyl group and the methyl group are on the same side of the double bond, while the hydrogen and the isopropyl group are trans.

Step2: Compare with the second molecule

The second molecule (top middle) is also (E)-3,4-dimethylpent-2-ene. It is simply a rotated version of the first molecule.

Step3: Compare with the fifth molecule

The fifth molecule (bottom middle) is also (E)-3,4-dimethylpent-2-ene. It is another orientation of the same structure.

Step4: Analyze the third molecule

The third molecule (top right) is (2Z,4E)-3,4,5-trimethylhepta-2,4-diene. It contains two double bonds with specific stereochemistry.

Step5: Compare with the fourth molecule

The fourth molecule (bottom left) is (2Z,4E)-3,4,5-trimethylhepta-2,4-diene. This is the same molecule as the third one, just rotated.

Step6: Compare with the sixth molecule

The sixth molecule (bottom right) is (2Z,4E)-3,4,5-trimethylhepta-2,4-diene. This is also the same molecule as the third and fourth ones.