Question

Sketch the expected proton NMR spectra of 3,3- dimethylbutanal.

Short answer

Nmr spectra graph

Step-by-step solution

Data for the above spectra

Generally methyl protons show 0.94 ppm chemical shift and CH₂proton shows 2.26 ppm chemical shift and the proton attaché to the carbo attached to carbonyl show nearly 9.72 ppm chemical shift with respect to tms in H¹ nmr spectroscopy.

Protocol of the H-1 NMR Prediction (Lib=SU Solvent=DMSO 300 MHz):

Node Shift Base + Inc. Comment (ppm rel. to TMS)

CH 9.72 9.60 CHO

0.12 1 -C

CH₂ 2.26 1.37 methylene

1.07 1 alpha -C=O

-0.18 3 beta -C

CH₃ 0.94 0.86 methyl

0.10 1 beta -C-R

0.10 2 beta -C

-0.12 general corrections

CH₃ 0.94 0.86 methyl

0.10 1 beta -C-R

0.10 2 beta -C

-0.12 general corrections

CH₃ 0.94 0.86 methyl

0.10 1 beta -C-R

0.10 2 beta -C

-0.12 general corrections

1H NMR Coupling Constant Prediction

shift atom index coupling partner, constant and vector

9.72 1

2 6.2 H-C(sp2)-CH-H

2.26 2

1 7.0 H-CH-C-H

0.94 4

0.94 6

0.94 7