(S)-Thalidomide (C₁₃H₁₀N₂O₄) - R or S Configuration
Is (S)-Thalidomide R or S?
(S)-Thalidomide (C₁₃H₁₀N₂O₄) has 1 chiral center. The teratogenic enantiomer of the infamous drug. The chiral center connects a phthalimide nitrogen and a glutarimide ring. Nitrogen directly bonded takes priority 1, then the C=O path beats the CH₂ path due to oxygen at the second atom level.. The configuration is S based on CIP priority rules.
| Formula | C₁₃H₁₀N₂O₄ |
| Name | (S)-Thalidomide |
| Number of Chiral Centers | 1 |
| Configuration(s) | S |
| Difficulty | Advanced |
Chiral Center Analysis
(S)-Thalidomide (C₁₃H₁₀N₂O₄) contains 1 chiral center. The teratogenic enantiomer of the infamous drug. The chiral center connects a phthalimide nitrogen and a glutarimide ring. Nitrogen directly bonded takes priority 1, then the C=O path beats the CH₂ path due to oxygen at the second atom level.. Each chiral center is analyzed below using CIP (Cahn-Ingold-Prelog) priority rules to determine R or S configuration.
CIP Priority Assignment
The four substituents on the chiral center are ranked by atomic number of the directly attached atom, with ties broken by exploring outward along each branch.
- Priority 1: -N(phth) - Phthalimide nitrogen directly bonded (atomic number 7) - highest first-atom priority
- Priority 2: -C(=O)N - Glutarimide C=O path: C bonded to O, O (phantom from =O), N at second level - O(8) wins
- Priority 3: -CH₂CH₂ - Glutarimide CH₂ path: C bonded to C, H, H at second level - C(6) < O(8)
- Priority 4: H - Hydrogen always lowest (atomic number 1)
R/S Configuration
With the lowest priority group (priority 4) oriented away from the viewer, the remaining three substituents trace a counterclockwise path from priority 1 to 2 to 3. This gives the S configuration.
Interactive stereochemistry explorer with guided walkthroughs and practice quizzes.
Assign R/S Configuration for (S)-Thalidomide Step by StepRelated Topics
L-Isoleucine - R or S?
Determine the R/S configuration of L-Isoleucine
L-Tryptophan - R or S?
Determine the R/S configuration of L-Tryptophan
L-Threonine - R or S?
Determine the R/S configuration of L-Threonine
Isomer Explorer
Compare enantiomers, diastereomers, and constitutional isomers in 3D
Drug Chirality
See how chirality affects drug activity with real pharmaceutical examples
Bromochlorofluoromethane - R or S?
Determine the R/S configuration of Bromochlorofluoromethane