Assigning Priority in a Double-Bonded System

Which groups would be assigned a HIGHER priority for each sp2 carbon atom in the double-bond, C1: CH2OCH3 or CH2OH and C2: Br or Cl?

The higher priority groups for each sp2 carbon atom in the double-bonded system would be CH2OCH3 (C1) and Br (C2).

Explanation:

In a double-bonded system, the higher priority groups for each sp2 carbon atom are determined using the Cahn-Ingold-Prelog (CIP) priority rules. These rules prioritize substituents based on the atomic numbers of the atoms directly bonded to the carbon atom.

For C1: In CH2OCH3, the atoms directly bonded to the sp2 carbon are carbon (C), oxygen (O), oxygen (O), and hydrogen (H). The atomic numbers of these atoms are 6, 8, 8, and 1, respectively. Since oxygen (O) has a higher atomic number than carbon (C), the group CH2OCH3 is assigned a higher priority than CH2OH for C1.

For C2: When comparing Br and Cl, bromine (Br) has a higher atomic number of 35 compared to chlorine (Cl) with an atomic number of 17. Therefore, Br is assigned a higher priority than Cl for C2.

Combining the results, the higher priority groups for C1 and C2 in the double-bonded system are CH2OCH3 and Br, respectively. Hence, the correct answer is option (a) C1: CH2OCH3 and C2: Br.