IB Chemistry R3.4 R3.4.13
R3.4.13 HL

Reaction Pathways & Synthesis

Multi-step synthesis, retrosynthesis, and functional group interconversions.

📘 IB Understanding

Organic synthesis involves planning a sequence of reactions to convert a starting material into a desired product. Retrosynthesis works backwards from the target molecule to identify suitable starting materials and reagents.

Key Functional Group Interconversions

ALCOHOL ALKENE HALOALKANE ALDEHYDE CARBOXYLIC ACID ESTER + HX or H₂O NaOH(aq) [O] distil [O] + acid, H⁺ cat.

Key Reagents Summary

ConversionReagents / Conditions
Alkene → AlcoholSteam (H₂O), H₃PO₄ catalyst, 300 °C
Alkene → HaloalkaneHBr or HCl (electrophilic addition)
Haloalkane → AlcoholAqueous NaOH, reflux (SN2)
Haloalkane → AlkeneEthanolic KOH, heat (elimination)
Primary alcohol → AldehydeK₂Cr₂O₇/H₂SO₄, distil
Aldehyde → Carboxylic acidK₂Cr₂O₇/H₂SO₄, reflux
Alcohol + Acid → EsterH⁺ catalyst, reflux
Aldehyde/Ketone → AlcoholNaBH₄ (reduction)

📋 Exam Tip

In synthesis questions, always state the reagents, conditions (temperature, catalyst, solvent), and type of reaction for each step. Practice working backwards from the target molecule (retrosynthesis) to find the most efficient route.

← R3.4.12 Organic RedoxFlashcards →