(a)
(i)
State the number of peaks that would be seen in the carbon-13 NMR spectrum of .
[ 1 ]
[Maximum number: 1]
Serotonin can be synthesised from the amino acid tryptophan in two steps.
(a)
Serotonin is converted by enzymes in the liver to compound M.
[ 1 ]
(i)
By reference to the Data Booklet, suggest how the infra-red spectrum of M would differ from that of serotonin.
[ 1 ]
(a)
(i)
Benzene reacts with each of these carbocations in separate Friedel-Crafts alkylation reactions.
In each reaction an organic compound with formula is formed. The number of peaks observed in the carbon-13 NMR spectrum of each compound is given.
Suggest the structures for the three other compounds.
[ 4 ]
[Maximum number: 3]
Phenylethanone is an important chemical with many uses.
phenylethanone
(a)
Phenylethanone can be used as a starting material to make phenylethene in a two-step synthesis.
phenylethene phenylethanone
D
step 2
[ 3 ]
(i)
State the number of peaks in the C-13 NMR spectrum of phenylethene.
[ 1 ]
(ii)
Suggest C-13 chemical shift ranges expected for the different types of carbon environment in phenylethanone.
[ 2 ]
(a)
Complete Table 4.1 to show the number of peaks observed in the carbon- 13 NMR spectrum for W and Z.
Table 4.1
[ 1 ]
(a)
A sample of pyruvic acid, , is analysed by carbon- 13 NMR spectroscopy. Three peaks are observed.
Complete the table by:
- circling the carbon atom responsible for the chemical shift
- stating the hybridisation of the circled carbon atom.
[ 2 ]
(a)
A sample of pyruvic acid, , is analysed by carbon- 13 NMR spectroscopy. Three peaks are observed.
Complete the table by:
- circling the carbon atom responsible for the chemical shift
- stating the hybridisation of the circled carbon atom.
[ 2 ]
(a)
Predict the number of peaks in the carbon-13 NMR spectra of W and Z.
[ 2 ]
(a)
(i)
Deduce the number of peaks that would be present in the carbon-13 NMR spectrum of benzophenone.
number of peaks
[ 1 ]
(ii)
Identify two different environments of carbon atom that would result in different chemical shift ranges in this carbon-13 NMR spectrum of benzophenone.
[ 2 ]
(a)
Polyhydroxyamide is a fire-resistant polyamide which is formed from the two monomers, F and G.
F
G
[ 2 ]
(i)
Predict the number of peaks that will be seen in the carbon-13 NMR spectra of F and G.
[ 2 ]