Answer
R isomer
Work Step by Step
Remember that a chiral center is a C bonded to 4 unique groups.
To determine R or S chirality, prioritize each group based on atomic number (starting from one atom out from the central C and branching out successive atoms). The highest atomic number group is the highest priority, while the lowest atomic group is the lowest priority.
In order from highest priority to lowest,
1 = OH
2 = CH2-OR
3 = CH2-NHR
4 = H
Then, arrange molecule so the 4th priority group is facing away from you. Drawing a circle from 1 to 2 to 3 should either go in the clockwise or counterclockwise direction.
Clockwise = R
Counterclockwise = S
