(S)-3-Methylpent-1-en-3-ol (C₆H₁₂O) - R or S Configuration

Chiral Center Analysis

(S)-3-Methylpent-1-en-3-ol (C₆H₁₂O) contains 1 chiral center. A quaternary stereocenter with NO nitrogen or carboxyl group. The chiral carbon has OH, a vinyl group, an ethyl group, and a methyl - no hydrogen. Tests understanding of double bond phantom atoms in CIP.. 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: -OH - Oxygen directly bonded (atomic number 8) - highest first-atom priority
• Priority 2: -CH=CH₂ - Vinyl: C bonded to C, C, H at second level - double bond creates phantom C atom, giving two C's vs ethyl's one
• Priority 3: -CH₂CH₃ - Ethyl: C bonded to C, H, H at second level - single bond to one C, loses to vinyl's phantom double C
• Priority 4: -CH₃ - Methyl: C bonded to H, H, H - lowest priority (no hydrogen on this chiral center!)

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.

Related Topics