(S)-3-Methylhexane (CH₃CH₂CH(CH₃)CH₂CH₂CH₃) - R or S Configuration

Chiral Center Analysis

(S)-3-Methylhexane (CH₃CH₂CH(CH₃)CH₂CH₂CH₃) contains 1 chiral center. A branched alkane with all-carbon substituents. Requires comparing chain length at each level to resolve CIP priorities - propyl > ethyl > methyl.. 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: -CH₂CH₂CH₃ - Propyl: C→C→C chain - longest, wins at third atom level over ethyl
• Priority 2: -CH₂CH₃ - Ethyl: C→C chain - longer than methyl (reaches C at second level) but shorter than propyl
• Priority 3: -CH₃ - Methyl: C bonded only to H - loses to ethyl and propyl at second atom level
• 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.

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