1. Synthesis of Chiral Drugs Group Members: Lim Seok Ting 10S76 Angie Phua 10S7A

2. What is our project about?
Synthesis of Phytophthora insect mating hormone
Phytophthora: devastating plant pathogens
Causes substantial yield losses in agricultural crops worldwide

3. What is our project about? (Cont’d)
Synthetic insecticide that can effectively kill pests
Hormone introduced during sexual reproduction of Phytophthora
20-step complex process
Unique insecticide: exhibits various chiral properties and chiral centres

4. Introduction to Experimental Techniques and Equipment

5. Thin Layer Chromatography (TLC)
Similar to paper chromatography
Carried out on a piece of glass coated with a thin layer of silica gel
Technique used to separate mixtures and identify compounds
Used to monitor reactions

6. VS

7. Monitoring Reactions Reactants  Product Pencil Line Reactant Spot
Product Spot
Co-spot Spot

8. How It Works?
Different compound have different solubility in various solvents (Hexane : Ethyl Acetate 1:1)
Silica Gel – SiO2
Si-O Bonds – Polar
Substance is highly polar  interact with silica gel  travel a shorter distance
Substances non-polar  travel a longer distance up TLC plate

9. Flash Column Chromatography
Used to purify chemical compounds, isolate desired products from mixtures (usually carried out after TLC analysis)
Utilizes a glass column filled silica gel
Sample to be separated placed on top
Flushed with solvent (hexane: EA 1:2)
External pressure applied  solvent runs through the column  compounds become separated

10. Experimental Setup
Mobile Phase
Stationary Phase

11. How it Works? Stationary Phase VS Mobile Phase
Individual components are retained by the stationary phase differently
separate from each other while running at different speeds through the column.
At the end of the column, they elute one at a time.
Eluent is collected in a series of fractions.

12. Rotary Evaporator
Used for removal of solvents from samples (usually done after Column Chromatography)
Via Evaporation and Condensation
Low pressures in evaporator lowers boiling point of solvents

13. Video for simplicity
that the centrifugal force and the frictional force between the wall of the rotating flask and the liquid sample result in the formation of a thin film of warm solvent being spread over a large surface.
the forces created by the rotation suppress violent, unpredicted boiling ("bumping").
A key disadvantage in rotary evaporations, besides its single sample nature, is the potential of some sample types to bump, e.g. ethanol and water, which can result in loss of a portion of the material intended to be retained.

14. Further research work Ongoing research work
Continue attachment at NTU (Nov-Dec)
Focus on synthesis of mating hormone using 20-step process

15. THE END Thank you!