This document discusses NMR interpretation and provides examples of summarizing NMR data in 3 sentences or less: 1) It describes common NMR splitting patterns such as doublets, triplets, and multiplets based on the number of equivalent protons coupled. 2) It explains how to calculate the degree of unsaturation in a molecule from its molecular formula by determining the number of hydrogens missing based on the parent hydrocarbon. 3) Key aspects of NMR data to summarize are listed as the number of signals, their intensities, and splitting patterns.

1. NMR Interpretation
Prepared By :
Mahendra G S
M-Pharm,Pharmaceutical
Chemistry
JSSCP, MYSURU

3. Splitting Patterns of Common Multiplets
Number of equivalent Appearance Intensities of lines
protons to which H of multiplet in multiplet
is coupled
1 Doublet 1:1
2 Triplet 1:2:1
3 Quartet 1:3:3:1
4 Pentet 1:4:6:4:1
5 Sextet 1:5:10:10:5:1
6 Septet 1:6:15:20:15:6:1

4. Degree of unsaturation
Because of the presence of a double bond, alkenes have
two fewer hydrogens than the corresponding parent
hydrocarbon.
For example, ethene (H2C=CH2) has the molecular
formula C2H4 and ethane (CH3CH3) has the formula
C2H6 (following the 2n + 2 rule).
Cycloalkanes, likewise, have two fewer hydrogen's than
the parent hydrocarbon since two of the valences are
utilized to close the ring: cyclohexane is C6H12, while
hexane is C6H14.

5. Knowing this relationship, it is possible to take a molecular
formula and calculate the degree of unsaturation; that is, the
total number of multiple bonds or rings in a molecule.
This information can then be utilized in the conversion of
analytical data into structural possibilities.
For hydrocarbons, the process is simple:
take the parent hydrocarbon and calculate the number of
hydrogens using the 2n + 2 rule,
every two hydrogens that are "missing" in the analysis of the
unknown represents one degree of unsaturation (DU).

7. 1. number of signals
2. their intensity (as measured by area under peak)
3. splitting pattern (multiplicity)

8. 2-pentanone, C5H10O

22. 3-methylaniline

26. 4-t-butylbenzoic acid

28. 5-methyl-2-isopropylphenol
also known as thymol

32. 3-butyl pyridine