CIE Mar 2017 v2 Paper 4 Q8

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20 The root of the ginger plant contains compounds with medicinal and flavouring properties. Three of the more important compounds are gingerol, shogaol and zingerone. (a) The structure of gingerol is shown. The CH3O group in gingerol is unreactive. PMT OH HO CH3O gingerol Gingerol reacts with acidified potassium dichromate(VI). State the type of reaction and the functional group change which occurs during this reaction. type of reactionfunctional group change fromto[1] (b) The structure of shogaol is shown. shogaol HO CH3O (i) State the type of reaction needed to convert gingerol into shogaol.[1] (ii) State the reagents and conditions needed to convert gingerol into shogaol. reagentsconditions[1]UCLES 2017 9701/42/F/M/17<br /> 21 (iii) Shogaol reacts with hot, concentrated acidified manganate(VII) ions to form two organic products, Q and R. Draw the structures of Q and R. PMT [2] (c) Zingerone is formed from gingerol. Some reactions of zingerone are shown. Complete the table to identify the functional groups in zingerone. reagent and conditions observation functional group in zingerone indicated by the observation benzenediazonium chloride, 5 C, alkaline solution red ppt. 2,4-dinitrophenylhydrazine orange ppt. warm with Tollens reagent no change [2] [Total: 7]UCLES 2017 9701/42/F/M/17 [Turn over<br />

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