NMR Practice: C 4 H 10 O Given a molecular formula and an NMR spectrum, what is the structure of the compound?

3 H 2 H

NMR Practice – C

6

H

12

O

2 ratio 1 : 3.0

integral

NMR : C 4 H 8 O 2

3 H 2 H q 3 H t

8.00

7.00

6.00

5.00

4.00

3.00

2.00

1.00

0.00

Common Patters for Proton NMR 1. triplet (3H) + quartet (2H) 2. large double (6H) + muliplet 3. large singlet (9H), ~1 ppm 4. multiplet ~7.2 ppm (4-5H) 5. singlet 3.5 ppm (3H) 6. singlet 2.1 ppm (3H) ethyl group isopropyl t-butyl group aromatic ring -OCH 3 group H 3 C-C=O (methyl ketone)

NMR Spectrometer - schematic

6

C 4 H 7 ClO 2

4 H m

NMR : C

10

H

14 1 H m 3 H s 6 H d

9

1 H NMR : C 6 H 12

10

1 H NMR : C 5 H 12 O

br

(doublet)

11

1 H NMR : C 5 H 10 O

3H 2H 1H 1H 1 H NMR : C 9 H 10 11 Hz 3 H doublet J = 8 Hz