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

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

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

Introduction to Experimental Techniques and Equipment

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

VS

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

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

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

Experimental Setup Mobile Phase Stationary Phase

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.

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

Video for simplicity http://www.youtube.com/watch?v=dKQIdSDso5E&feature=related 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.

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

THE END Thank you!