An organic compound E contains carbon, hydrogen and oxygen only.
i)
The accurate relative atomic masses, Ar , of the three elements in E are shown in the table.
Element |
Ar |
hydrogen |
1.0078 |
carbon |
12.0000 |
oxygen |
15.9949 |
E contains five carbon atoms and gives a molecular ion peak at m / z = 102.0678 in its mass spectrum.
Deduce the molecular formula of E.
(1)
ii)
Aqueous sodium hydrogencarbonate is added to a sample of E.
No effervescence occurs.
State what can be deduced by this observation.
(1)
iii)
The infrared spectrum of E has an absorption in the range 1750 – 1735 cm−1.
Name the functional group in E.
(1)
iv)
Data from the high resolution proton NMR spectrum of E is shown.
Peak |
Chemical shift,
/ ppm for TMS
|
Splitting pattern |
Relative peak area |
A |
4.02 |
triplet |
2 |
B |
2.05 |
singlet |
3 |
C |
1.65 |
sextet |
2 |
D |
0.95 |
triplet |
3 |
Deduce the structure of E.
Justify your answer by labelling the protons responsible for each peak.
(3)