OC-05: Alcohols, Phenols & Ethers
         |
         ├── OC-06: Aldehydes & Ketones
         │     └── 1° alcohol --[PCC]--> aldehyde (feeds into carbonyl chemistry)
         │     └── 2° alcohol --[PCC]--> ketone (same)
         │
         ├── OC-07: Carboxylic Acids
         │     └── 1° alcohol --[$KMnO_{4}$]--> carboxylic acid (final oxidation product)
         │     └── Fischer esterification: RCOOH + R'OH → ester
         │
         ├── OC-02/03: Reaction Mechanisms
         │     └── Williamson = SN2 mechanism
         │     └── Lucas test = SN1 mechanism (3° > 2°)
         │     └── Saytzeff rule = E2 mechanism (competing with SN2)
         │
         ├── OC-08: Benzene / Aromatic Chemistry
         │     └── Phenol = activated benzene for EAS
         │     └── -OH as ortho/para director
         │
         └── Physical Chemistry: Acid-Base
               └── pKa values: phenol (10) < water (15.7) < alcohol (16-18)
               └── Resonance stabilization = equilibrium shift toward products

Cross-Chapter Principle: The carbocation stability order (3° > 2° > 1°) appears in ALL these chapters — Lucas test, dehydration ease, SN1 rate, and Markovnikov's rule all trace back to the same principle.