OCR A Jun 2015 Paper 4 Q3

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3 Many -amino acids have several functional groups. 10 (a) Serine, shown below, is a naturally occurring -amino acid. (i) In the boxes below, draw the structure of the organic compounds formed by each reaction. HO OH H H C C NH2 H serine Na2CO3(aq) reaction 1 reaction 2 HO CH2 and H2SO4 (ii) Suggest a use for the organic compound formed by reaction 2.[1] [3] (iii) Serine is commonly used in organic synthesis. One possible method of synthesising serine is shown below. CH3COO H C H H C Cl H C H OH reaction 3 CH3COO HO OH H H C C NH2 H serine reaction 5 CH3COOOCR 2015 H C H H C H H C NH2 H C H OH reaction 4 H C NH2 OH<br />
 11 Complete the following: Reagent and conditions used for reaction 3.Type of reaction for: reaction 4reaction 5[3] (b) Compound E, C4H7NO, is one of two optical isomers. It can be oxidised by Tollens reagent to an -amino acid, F. The -amino acid F forms two different polymers, G and H. Polymer G has the empirical formula C4H7NO2. Polymer H has the empirical formula C4H5NO. Suggest structures for compound E and compound F.Draw repeat units of polymer G and polymer H.Describe how F forms G and H.OCR 2015 [6] Turn over<br />
 (c) Poly(glutamic acid) is a polymer of the amino acid, glutamic acid. 12 H H N C HOOC H C H H C H O C repeat unit of poly(glutamic acid) (i) Draw the structure of glutamic acid. (ii) A student tried to prepare poly(glutamic acid) from glutamic acid. No polymer was found in the product mixture. The student isolated the two major compounds in the mixture. The mass spectra of these two compounds showed molecular ion (M+) peaks at m / z = 129 and m / z = 258. Suggest structures for these two compounds. [1] [2]OCR 2015<br />
 (d) Polymer J has been recently developed by scientists. The repeat unit of polymer J is shown below. 13 CO(CH2)4CONHC(CH3)2CH2O polymer J (i) What are the functional groups in polymer J?[1] (ii) Two different monomers react to form polymer J. Draw the structures of the two monomers in the boxes below. Display the functional groups in each monomer. [2] (iii) Polymer J is used in hair spray. It can be washed away easily with hot water. Suggest why polymer J is able to be washed away easily with hot water.[1] [Total: 20]OCR 2015 Turn over<br />

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