Top 10 High-Yield Reactions in HSC Organic Chemistry & How to Remember Them

Why Organic Chemistry Feels Overwhelming

Many HSC students struggle with Organic Chemistry because they try to memorize reactions in isolation rather than understanding the underlying reaction mechanisms and functional group conversions.

1. Grignard Reagent ($R-Mg-X$) Conversions

Grignard reagents are the Swiss Army knife of organic synthesis. By reacting with formaldehyde, aldehydes, or ketones, you can synthesize primary, secondary, and tertiary alcohols respectively.

Formaldehyde + Grignard $\rightarrow$ $1^\circ$ Alcohol

Acetaldehyde + Grignard $\rightarrow$ $2^\circ$ Alcohol

Acetone + Grignard $\rightarrow$ $3^\circ$ Alcohol

2. Aldol Condensation vs Cannizzaro Reaction

The golden rule: Does it have an $\alpha$-hydrogen?

If yes (like Ethanal): Undergoes Aldol Condensation with dilute NaOH.

If no (like Methanal or Benzaldehyde): Undergoes Cannizzaro Reaction (disproportionation) with concentrated 50% NaOH.

3. Wurtz and Wurtz-Fittig Reactions

Used for ascending alkane chains. Keep in mind that symmetrical alkanes give the highest yield, while cross-Wurtz creates a mixture of products.

4. Carbylamine Test for Primary Amines

Reacting primary aliphatic or aromatic amines with chloroform and alcoholic KOH yields an intensely foul-smelling isocyanide ($R-NC$). This is the definitive test for primary amines!

> Pro Tip for HSC 2026: Create a 1-page visual roadmap mapping Benzene $\rightarrow$ Chlorobenzene $\rightarrow$ Phenol $\rightarrow$ Salicylic acid (Aspirin). Revision becomes 10x faster!