QuestionStereochemistry / R and S
What is the correct configuration of C2 and C3 carbons in the following compound?
- (a) 2R, 3S
- (b) 2S, 3R
- (c) 2R, 3R
- (d) 2S, 3S
Answer: (c) 2R, 3R
C2: OH > N(CH₃)₂ > C3 (Cl,C,C) > CH₃. C3: Cl > C2 (O,N,C) > CH₂CH₃ > CH₃. In both, lowest priority sits on a horizontal bond, so reverse the drawn sense: C2 → R, C3 → R → (c).