Question

7.27 20180528_Inova_500_isopropyl acetate-PROTON_01 5.03 5.02 5.01 66 OL84.974.98 4.96 Chemical Shift (ppm) 4.0 .......... 2.02 .. ......

(b)How can you use ¹H NMR to distinguish between isopropyl ethanoate and methyl 2-methylpropanoate.

Answer 1

A)

Signal	Chemical Shift	Splitting pattern	No of H neighbours	Integration of protons	Circle or highlight the protons that give rise to signal
A	4.99	Septet	6	1
B	2.02	Singlet	0	3
C	1.24	doublet	1	6

B) To distinguish between isopropyl ethanoate and methyl 2-methylpropanoate, we can use H1 NMR

In case of Isopropyl ethanoate, there is only one hydrogen atom attached to carbon atom directly attached to oxygen atom thus there would be 1 H atom showing chemical shift between 4-5 ppm (splitting pattern- septet) whereas in case of methyl 2-methyl propanoate there would be three such hydrogen atoms attached to carbon atom directly attached to oxygen atom thus there would be 3 H atom showing chemical shift between 4-5 ppm (splitteing pattern- singlet). Thus with integration of protons we can easily distinguish between them