Answer
1 - O
2 - (Left) Carbon
3 - (Right) Carbon
4 - H
Work Step by Step
1. Identify the stereocenter.
2. List all atoms connected to the stereocenter, and rank them by the atomic number.
- O, H, C, C
Ranked by atomic number:
- O, C, C, H
3. As we can see, there are 2 equal atoms.
- Find the closest variation on the chains (Double bond, Substituent).
- The chain with the closer variation gets priority.
In this case:
- Left chain: Double bond and Methyl on the third carbon.
- Right chain: Double bond on the third carbon.
Therefore, the left carbon gets priority.
4. Put the numbers on the stereocenter atoms:
1 - O
2 - (Left) Carbon
3 - (Right) Carbon
4 - H
