CHEM 2320-2
TEST 3 Answers
Dr. Bachrach
Nov. 19, 2012

1) Provide the IUPAC name of the following compounds.

(3S)-6-ethyl-N,N,2-trimethyloctan-3-amine

2) Provide the mechanism for the reaction below.

3) A compound with molecular formula C8H18N has the IR, 13C NMR and 1H NMR spectrum below. Identify the structure of the compound. For the 1H NMR spectrum, identify the H source of each signal.

The IR indicates an N-H bond by the small peaks around 3600 cm-1. The 13C NMR tells us that there are three unique carbons. The molecular formula tells us that there are no degrees of unsaturation so the molecule must have some symmetry.

In the 1H NMR, the peak at 0.98ppm is a methyl group split into a doublet, so its a CH3-CH fragment. The peak at 2.4 is a methylene group shifted downfield because of the adjacency to a nitrogen. It too is a doublet so we know NH-CHn-CH, where the underlined H is the peak at 2.4ppm. The small peak at 1.1ppm is probably the NH, and the multiplet at 1.8 is due to complex coupling. To put this all together:

where the methyl hydrogens (a) are observed as a doublet at 0.9ppm, the methyne hydrogen (b) is the multiplet at 1.8ppm, the methylene hydrogens (c) are the doublet at 2.4ppm, and the NH (d) appears as the singlet at 1.1ppm.

4) Provide the product(s) of the following reactions:

a)

b)

c)

5) Provide the necessary reagent(s) to enable the following transformations. Multiple steps might be required.

a)

b)

c)

6) Draw and fully name one of the cyclic hemiacetal structures of talose (shown below).

α-L-alopyranose

β-L-talopyranose

7) Propose a multi-step synthetic pathway that will take A into B. You may use whatever reagents you desire.