OCR A Jun 2016 Paper 4 Q6

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There are several isomeric alcohols with the formula C5H11OH. 16 (a) Pentan-1-ol, CH3(CH2)3CH2OH, can be prepared in the laboratory by the reduction of an aldehyde. State a suitable reducing agent for this reaction and write an equation to show the preparation of pentan-1-ol. Use [H] to represent the reducing agent in the equation. Reducing agentEquation[2] (b) Compound F is a structural isomer of C5H11OH. Compound F is converted to compound G when heated under reflux with acidified potassium dichromate(VI) solution. Compound G reacts with 2,4-dinitrophenylhydrazine to form an orange solid but compound G does not react with Tollens reagent. The 13C NMR spectrum of compound G is shown below. 200 180 160 140 120 100 80 60 40 20 ppm Compound H is a carboxylic acid. In a titration, 0.211 g of carboxylic acid H requires 22.8 cm3 of 0.125 mol dm3 NaOH for neutralisation. Compound F reacts with compound H in the presence of concentrated sulfuric acid to form organic compound I.OCR 2016<br />
 Identify compounds F, G, H and I and draw their structures in the boxes below. Show your working only for the identification of compound H. 17[7]OCR 2016 Turn over<br />
 18 (c) Compound J is another structural isomer of C5H11OH. The 1H NMR spectrum of J is shown below. The numbers next to each peak are the relative peak areas. 10 6 3 Chemical shift, (cid:98)(cid:3)/ ppm Identify compound J and draw its structure in the box below. END OF QUESTION PAPER [1] [Total: 10]OCR 2016<br />

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