Please suggest a proper structure for each of the nine compounds. And explain th
ID: 528802 • Letter: P
Question
Please suggest a proper structure for each of the nine compounds. And explain the NMR spectrum and show what peaks are due to which protons, also explained the splitting of the peaks based on your structure. Remember when interpreting nmr (proton) spectra: 1. The position of the peaks (ppm) tells you what kinds of protons you have. See chart. 2. The area under each peak (integration) tells how many of those types of protons are present. 3. The splitting of peaks tells you how many protons are found on an adjacent carbon atom. a. A singlet means that there are no protons on the carbon atoms adjacent to this peak. b. A doublet means that there is one proton on a carbon adjacent to this peak (methine) c. A triplet means that there are two hydrogen's on an adjacent carbon (methylene group) d. A quartet means that there are three hydrogen's on the adjacent carbon (methyl group). The ethyl group is characterized by a three-proton triplet and a two-proton quartet) e. A heptuplet means that there are six protons (two methyl groups) next door. An Isopropyl group is characterized by a six-proton doublet and a one-proton heptuplet. f Sometimes the multiple is too complicated and you may have non first- order couplingsExplanation / Answer
5. The structure of the compound is CH3-COO-CH2CH3.
The splitting of peaks gives us an idea about the number of protons that are found on an adjacent carbon.
A quartet at 4.1 ppm shows that there are 3 hydrogen's on the adjacent carbon (methyl group) and this is probably attached to -O-CH2. A triplet at 1.2 ppm shows that there are 2 hydrogen's on the adjacent carbon (methylene group). So, there must be an ethyl group attached to an ester group which is characterised by a three-proton triplet and a two-proton quartet.
A singlet at 2.0 ppm shows that there are no protons on the carbon atom adjacent to it. This peak is characteristic of CO-CH3. Hence the structure of the compoiund is CH3-COO-CH2CH3.
6. The structure of the compound is CH3-O-CO-CH2CH3.
The splitting of peaks gives us an idea about the number of protons that are found on an adjacent carbon.
A singlet at 3.7 ppm shows that there are no protons on the carbon adjacent to it. This peak is characteristic of O-CH3. A quartet at 2.4 ppm shows that there are 3 hydrogen's on the adjacent carbon (methyl group) and this (probably -CH2-CO group) should be attached to a carbonyl group. A triplet at 1.2 ppm shows that there are 2 hydrogen's on the adjacent carbon (methylene group). So, there must be an ethyl group attached to a carbonyl group which is characterised by a three-proton triplet and a two-proton quartet.
Hence the structure of the compoiund is CH3-O-CO-CH2CH3.
Compound 5 and 6 are isomers.