OCR A Jun 2013 Paper 4 Q4

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4 Compound E, shown below, is an alcohol that is found in oak wood. It is formed by the breakdown of cellulose. 12 OH OH compound E Compound E can be converted into compound G as shown in the flowchart below. OH OH excess K2Cr2O7/H2SO4 reflux compound E reaction 1 compound F reaction 2 reagentOH OH compound G (a) (i) Complete the flowchart to show the structure of the organic compound F and the reagent [1] needed for reaction 2.OCR 2013<br />
 (ii) What would you observe during reaction 1? 13[1] (iii) In reaction 1, compound E was heated under reflux with excess K2Cr2O7/H2SO4. Suggest why these conditions were used, rather than the reaction mixture being distilled during the process.[1] (iv) Name the type of reaction taking place in reaction 2.[1] (b) Describe a chemical test that you could use to detect the presence of a carbonyl group in an organic compound. ReagentObservation[2] (c) Compound E is a single stereoisomer. (i) Draw the skeletal formula of one other stereoisomer of compound E and state the type of stereoisomerism. type of stereoisomerism[2]OCR 2013 Turn over<br />
 (ii) 4.56 g of compound E was converted into compound G using the method shown in the flowchart on page 12. 14 3.15 g of compound G was formed. Calculate the percentage yield of compound G. Give your answer to three significant figures. The Mr of compound E is 160.0. percentage yield of compound G =% [3] (iii) Compound G is heated for several hours under reflux, in the presence of a concentrated sulfuric acid catalyst. An ester and a small inorganic molecule are formed. Complete the equation below to show the two products formed by this reaction. concentrated H2SO4 catalyst OH OH heat under reflux +[2] [Total: 13]OCR 2013<br />

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