Question

Draw the structure that would be responsible for the spectrum. To make interpretation a little easier, I have included the splitting type and number of hydrogens for each set of signals in the spectrum, from left to right. In other words, C4H8O; quartet (2H), triplet (3H), singlet (3H) means, that the three sets of peaks, starting from the left are a quartet due to two hydrogens, a triplet due to three hydrogens and a singlet due to three hydrogens.

CsHIoO2, septet (H), singlet (3H), doublet (6H) 11 10 9 8765 43210 ppm

Answer 1

Solution :-

Given data

Molecular formula = C5H10O2

1H NMR signals , septet (1H) , Singlet (3H) ,doublet (6H)

Lets first calculate the number of unsaturations

Parent hydrocarbon with the 5 carbon chain is the C5H12

So the there is the hydrogen deficiency of the 2 H

So number of unsaturations = 2/2 = 1

1 H giving septet means it has 6 protons on the neighboring carbons like CH-(CH3)2

6 H giving doublet means they are attached to the carbon bearing only 1 proton like CH-(CH3)2

3 H giving singlet means they do not have any neighboring protons.   Like CH3-C-

1H showing septet is much downfield therefore it may attached to the electron withdrawing group.

Now from this data following is the possible structure..

hicd 4tつ Sh 0 ク