PART B Conditions Acetone Solvent

Reagents and Equipment Weigh and place 300 mg (0.97 mmol) of erythro-2,3-dibromo-3-phenylpropanoic add (prepared in Experiment [D2]) and 300 mg (2.1 mmol) of potassium carbonate in a 10-mL round-bottom flask containing a magnetic stir bar. Add 5 mL of acetone that has been dried over sodium sulfate. Attach the flask to a reflux condenser and assemble the apparatus on an 80 °C sand bath. 

Reaction Conditions. Heat (bath temperature 80 °C) the mixture, with stirring, at reflux for 1 h. 

Isolation of Product. Allow the solution to cool to room temperature and HOOD then concentrate it to dryness in the hood on a warm sand bath under a gentle stream of nitrogen gas. Do not overheat  

Now add 5 mL of distilled water to dissolve the solid cake. A yellow oil appears at this point, forming a two-phase system. Using a Fhsteur pipet, transfer this aqueous-oily mixture to a 12-mL centrifuge tube. Rinse the round-bottom flask with a 2-mL portion of methylene chloride, which is then transferred to the centrifuge tube. Extract the aqueous phase with the CH2CI2 rinse and follow this extraction with two more extractions of the aqueous phase with 2-mL portions of methylene chlo-ride. Transfer the organic extracts to a second 25-mL Erlenmeyer flask using a Pasteur filter pipet and dry the combined extracts over anhydrous sodium sulfate for at least 10 min. 

Transfer the dried solution in 2- to 3-mL portions to a tared 5-mL coni-HOOD cal vial containing a boiling stone. Concentrate the solution in the hood on a warm sand bath under a gentle stream of nitrogen gas. Rinse the sodium sulfate with an additional 1 mL of methylene chloride and combine this rinse with the dried solution. Concentrate to yield a yellow oil, cis-T-bromostyrene. 

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