CIE Nov 2016 v2 Paper 4 Q6

Answers available below

Oleocanthal, Q, is a natural compound found in olive oil. It has antioxidant and anti-in ammatory properties and is thought to have a protective effect against Alzheimers disease. 10 PMT HO (a) Q shows optical and cis-trans isomerism. On the structure of Q above, circle the functional group that shows cis-trans isomerism and indicate with an asterisk (*) the chiral carbon atom. [1] (b) Q can be isolated from olive oil by partitioning between two solvents. (i) Explain what is meant by the term partition coef cient.[2] (ii) When 40.0 cm3 of hexane was shaken with 10.0 cm3 of a solution containing 0.25 g of Q in 10.0 cm3 of methanol, it was found that 0.060 g of Q was extracted into the hexane. Calculate the partition coef cient, Kpartition, of Q between hexane and methanol. Kpartition =[2]UCLES 2016 9701/42/O/N/16<br /> 11 (c) Complete the following table to show the structures of the products formed when Q reacts with the three reagents. reagent structure of product(s) type of reaction PMT excess Br2(aq) NaBH4 excess hot NaOH(aq) [6] (d) When a sample of Q synthesised in a laboratory was compared to a natural sample from olive oil, it was found that the therapeutic activity of the synthetic sample was lower. Suggest a reason for this.[1]UCLES 2016 9701/42/O/N/16 [Total: 12] [Turn over<br /> 12 BLANK PAGE PMTUCLES 2016 9701/42/O/N/16<br />

Show answer