17. Carbonyl compounds
A section of Chemistry, 9701
Listing 10 of 304 questions
The reaction producing tri-iodomethane can be used as a test for the presence of certain groups within a molecule. State the reagents and conditions used for this reaction. Write the structural formula of one functional group that would give a positive result with this iodoform reaction. What do you observe in a positive test? In the following table place a tick (✓) in the column against each compound that would give a positive result with this test, and a cross (✗) against each compound that would give a negative result. compound result CH3OH CH3CH2OH CH3CHO CH3CO2H CHO COCH3 The iodoform test can be used, along with other reactions, to work out the structures of unknown compounds. Use the information in the table below to deduce the structures of the compounds in the following scheme, and draw these structures in the boxes provided. hot concentrated acidified KMnO4 C7H12O C3H6O + C4H6O3 D E F Results of tests (✓ indicates a positive result; ✗ indicates a negative result) test results of tests with each compound D E F iodoform ✗ ✓ ✓ Fehling’s solution ✓ ✗ ✗ 2,4-dinitrophenyl- hydrazine reagent ✓ ✓ ✓ Na2CO3✗ ✗ ✓ structures D(C7H12O) E(C3H6O) F(C4H6O3) Treatment of compound F with NaBH4 gives compound G, C4H8O3. Heating G with Al2O3 gives a mixture of three isomeric unsaturated carboxylic acids H, J and K, C4H6O2, two of which are stereoisomers of each other. Suggest structures for G, H, J, and K, and name the type of stereoisomerism shown. G Al2O3 H + J + K type of stereoisomerism
9701_s11_qp_41
THEORY
2011
Paper 4, Variant 1
View
Questions Discovered
304