Which of the following groups has the highest priority according to the Cahn-Ingold-Prelog sequence rules? CH3 CH2OH CHO CH2Cl

The Cahn-Ingold-Prelog (CIP) sequence rules are used to assign priority to different groups attached to a chiral center in a molecule. The rules are as follows:

1. Atoms attached to the chiral center are ranked according to their atomic number. The atom with the highest atomic number gets the highest priority.

2. If there is a tie, the next atoms along the chain are considered.

3. If there is still a tie, the process continues until a difference is found.

Now, let's apply these rules to the groups you provided:

1. CH3: The first atom is Carbon (atomic number 6).
2. CH2OH: The first atom is Carbon (atomic number 6), but the next atom is Oxygen (atomic number 8).
3. CHO: The first atom is Carbon (atomic number 6), but the next atom is Oxygen (atomic number 8).
4. CH2Cl: The first atom is Carbon (atomic number 6), but the next atom is Chlorine (atomic number 17).

According to the CIP rules, the group with the highest priority is CH2Cl because Chlorine has the highest atomic number among the second atoms in the groups.