CHEM 2319-2
Test 1 Answers
Dr. Bachrach
2/11/11

1) Provide the IUPAC name for the following compounds.

2) Draw the structure of 1-methyl-4-pentylcycloheptene.

3) Starting from the left, identify the hybridization of each carbon atoms in the compound below:

4) Draw the Lewis dot structures of the following compounds:

a)

b)

5) Consider the molecule below, which is called glucose. The six member oxygen-containing ring adopts a geometry just like that of cyclohexane. There are many other possible sugar molecules that differ from glucose in the arrangements of the OH and CH₂OH groups – their relative cis and trans arrangements. Why do you think that glucose is the most widely found sugar in nature? Justify your answer.

Note that all of the substituents are in the equatorial position – and the equatorial position is the best place for the substituents to be, much better than axial. Any other sugar will have a different cis or trans arrangement which will force at least on substituent into an axial position. Therefore, glucose is the most stable sugar and likely to therefore be the most abundant one.

6) Assign the formal charges to all non-hydrogen atoms this neutral molecule.

This compound has an odd number of electrons and so some atom will not have a complete octet. So you need to come up with a reasonable Lewis dot structures, like the one above, but others are possible – and then assign the formal charge. For the above Lewis Dot Structure, all three carbons are neutral, the top oxygen is neutral, the right oxygen has a charge of -1 and the nitrogen has a charge of +1.

7) Draw the Newman projection for the three staggered conformations of4-ethyl-3-methylheptane viewing down the C₃-C₄ bond.

Me is the methyl group (CH₃). Et is the ethyl group (CH₂CH₃). Pr is the propyl group (CH₂CH₂CH₃).

8) Draw the most favorable conformation of the following compound: