1. Using IUPAC rules provide a name to each
structure below. Use common names for branched substituents were applicable. (6pts)
2. (a) Convert the semi-synthetic animal steroid shown below in bond-line form to its proper chair form
by drawing in the missing non-hydrogen groups in their proper orientation and circle the groups that are
axial. The skeleton is made up of the tetracyclic ring core. These 4 rings have been labeled A thru D for
(b) Identify the two fused rings that represent a trans-decalin system (1pt) __________________
(c) Identify the two fused rings that do not represent a decalin skeleton. (1pt) ___________________
3. (a) Sighting down the C1 → C2 bond, consider the bond-line structure shown below. Using the
Newman projection templates provided, draw all three staggered conformations in Newman projection
form in order of increasing stability about the C1 → C2 bond. (6pts) You may assume that iPr > Et > Cl
in terms of size.
(b) Sighting down the C3 → C4 bond, consider the bond-line structure shown below. Using the Newman
projection templates provided, draw all three eclipsed conformations in Newman projection form in
order of increasing stability about the C3 → C4 bond. (6pts)
(c) (i) Convert the chair structure below into its proper Newman projection using the template provided.
You need to fill in the empty boxes with the correct substituents (hydrogen and non-hydrogen groups).
Use the numbering scheme provided. (4pts)
(ii) Circle the bond-line structure below that best represents the same structure provided above in part c(i)
(iii) (1pt) Is the iPr group at C-1 in the chair axial or equatorial? ___________________
(iv) (1pt) Is the CH3 group at C-2 in the chair axial or equatorial? ___________________
4. For (a) circle the most relative stable structure. Show work by drawing relevant chair structures and/or
Newman projections (as needed) to clearly illustrate why. Explain your choice with a few words (no
more than one sentence). It is best practice here that only the most stable conformations for each
compound are being compared. For (b), provide a brief explanation for why chair 1 is more stable than
chair 2. (10pts)
5. (a) (3pts) Provide a systematic (IUPAC) name for the structure below. You may ignore
(b) Draw the structure of each compound below. Be sure to clearly show the relative stereochemistry.
Then, circle the compound that will have the highest heat of combustion. (4pts)
6. Draw and compare the Newman projections of when the OH groups are anti to each other versus
when they are gauche to each other. Then, explain in a few words why the compound is more stable in
the conformation where the OH groups are gauche to each other. (6pts)