Question

Unknown B-C NMR OLL COL 72.09 87.70, 72.09, 13C NMR (101 MHz, cdc13) 68.56, 39.78, 25.09, 23.13 WWWWWMWWN 105 100 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 ppi

Please help identify which compound these NMR's match.

If possible label the proton NMR peaks with the protons on the compound.

Answer 1

From 1H NMR data it is clear that molecule does not contain aldehyde, alkene, ester (as oxygen attached protons missing), any aromatic ring (as the substituted aromatic protons missing).

13C NMR data shows that compound does not contain any carbonyl derivative.

Therefore, following compounds can be neglected from the given molecules

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 16

There is possibility of only two compounds that is 14 and 15

Now lets take a look at number of protons observed in 1H NMR which indicates presence of 12 protons

Both the molecule have C8H12O formula

Internal alkyne having terminal methyl are shielded because of the alkyne which appears around 0-10 ppm in 13C NMR.

Therefore the given data matches with the compound number 15

68.56 39.78 25.09 OH 72.09 87.7 23.13 Chemical Formula: C8H120