Answer
(S,S) 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,
Center 1:
1 = NHR
2 = CH-2C
3 = CH2-C
4 = H
Center 2:
1 = C-2O
2 = C-N,C,H
3 = C-2C
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
Center 1,2 = S,S