Answer questions 4 and 5 Why was the potassium carbonate added during the isolat
ID: 523862 • Letter: A
Question
Answer questions 4 and 5 Why was the potassium carbonate added during the isolation of the product? Why was the bulk of the acetone boiled off prior to the extractions with dichloromethane? Why is it important that the reaction mixture was cooled to room temperature prior to the extractions with dichloromethane? Use the curved-arrow notation to draw the mechanism of the reaction of acetone and cis-1, 2-cyclohexanediol in the presence of hydrochloric acid to form the acetonide-3. Five-membered-ring acetonides formed in today's reaction even though it is structurally are possible for D-(+)-mannose to react with acetone to form six-membered-ring acetonides. This result is due to fact that five-membered-ring acetonides are more stable the thermodynamically than six-membered-ring acetonides. What is the structural basis for this fact? Draw annotated three-dimensional pictures of the following acetonides to illustrate your answer: a. the acetonide formed by 1, 2-ethanediol (ethylene glycol) and acetone acetonide formed by 1, 3-propanediol (trimethylene glycol) and acetone.Explanation / Answer
4. Potassium carbonate is added during the isolation of product to neutralize the acidic medium. It help all the mineral and protic impurities to go into water layer and more product (organic compound) is pulled into organic layer.
5. The bulk of acetone is boiled of prior to the extractions with dichloromethane because water and aqueous solutions are used in work-up. Acetone is soluble in water and the solubility of organic compound in acetone will make the extraction in dichloromethane difficlut.