Reducing Agents

1. Measuring Properties of Ethyl Acetoacetate

1. Take an IR of the starting material (ethyl acetoacetate).
2. Take a TLC using 40% ethyl acetate in 60% hexanes.

2. Reduction of Ethyl Acetoacetate with Sodium Borohydride

1. Add 1 mmol of ethyl acetoacetate to a round-bottom flask.
2. Add 5 mL of ethanol and swirl to mix completely.
3. Lower the beaker into an ice-water bath.
4. Weigh 1 mmol of sodium borohydride and slowly add to the stirred solution of ethyl acetoacetate.
   1. Add in small portions. The reaction is exothermic and bubbles vigorously.
5. Immediately after, monitor the reaction by TLC every few minutes until the reaction is complete.
6. Once complete, add 10 mL of water to the reaction mixture.
7. Transfer into a separatory funnel and extract with ethyl acetate (2x 30 mL).
8. Dry with DI water (1x 30 mL) and with brine (1x 30 mL).
9. Dry over sodium sulfate and filter into a round-bottom flask.
10. Evaporate the solvent on a rotary evaporator.
11. Take a TLC and IR of the reduction product.

3. Reduction of Ethyl Acetoacetate with Lithium Aluminum Hydride

1. Add 1 mmol of lithium aluminum hydride into a dry round-bottom flask and cap it with a septum.
2. Purge the flask with nitrogen gas using a nitrogen inlet line. Make sure to have an exit valve.
3. Add 10 mL of dry THF.
4. Place the round-bottom flask into an ice bath.
5. Make a solution of 1 mmol of ethyl acetoacetate into 3 mL of dry THF and slowly add dropwise into the reaction flask.
6. The reaction will vigorously bubble until all of the reagent is added.
7. Immediately after, monitor the reaction by TLC every few minutes until the reaction is complete.
8. Once complete, add 1 M HCl dropwise. The reaction will bubble vigorously until all of the LiAlH₄ is consumed.
9. Once consumed (no more bubbling), the septum can be removed and diluted with ethyl acetate (40 mL) and 1 M HCl (20 mL).
10. Transfer to a separatory funnel.
11. Extract with ethyl acetate (3x 50 mL).
12. Dry with brine (1x 50 mL).
13. Dry over sodium sulfate and filter into a round-bottom flask.
14. Evaporate the solvent on a rotary evaporator.
15. Take a TLC and IR of the reduction product.