Assignment #3 CHEM 2OD3 - ANSWERS
Student Number_____________________
Student Name______________________
1. Complete the following reactions by filling the blanks. Indicate all products (indicate major product(s) if
necessary) and stereochemistry where appropriate. When no reaction occurs write NR. [20]
a.
b.
c.
d.
e.
f.
g.
h.
i.
j.
2. A reaction was performed between 1-bromobutane and benzene in the presence of AlBr3. Four products were
isolated, all with molecular formula C10H14. The 1H NMR spectra of the four compounds are shown below.
i.
Draw the structures of the four compounds
ii.
Explain how the coupling pattern is consistent with the structure (use example of coupling constants,
if the spectra are clear enough)
iii.
Predict which of the compounds were formed in higher yield and which in lower yield
iv.
Draw a mechanism with curly arrows that would explain the results.
5H 2H 2H 2H 3H 5H 2H 1H 6H 5H 1H 2H 3H 3H 5H 9H Highest yields will come from products of the most stable cations (the rearrangement happens faster than the
Friedel Crafts) so tBu > sBu > iBu ~ nBu
3. Using the starting reagent shown below, propose a synthetic route for the following product. For carbon based
reactants, use only benzene or compounds with no more than 2 carbons. It will take several steps. [20]
4. Show the full mechanism for the following reaction (curly arrows). Show the reagents necessary to make it work
properly. Modify any of the starting materials if necessary. [10]
5. Using the following spectra given below, propose an appropriate structure for the compound. Determine the
unsaturation number of the compound, give peak splittings and assign peaks to the final structure. For IR peak
assignments (above 1500 cm-1), all functional groups should be accounted for including CH stretch. [20]
C6H14N2O2
1H
4H
1H
2H
2H 2H 2H
13
H NMR m s q t t s m s C NMR UN#  C6H14N2O2 = C6H12  UN = 1
OH – 2650-3150 cm-1
C=O – 1620 cm-1
NH – 1500cm-1
CH – 2950cm-1
6. Provide compounds/intermediates A-I. You may only use benzene and any 2 carbon compound you like.
Anything else you will have to synthesize. [10]