CHEM 321 Organic Chemistry I Exam 2 10/16/09 Name:

Name:
CHEM 321
Organic Chemistry I
Exam 2
10/16/09
Part I. Short Answer – (43 total number points) Answer all parts for the following
questions
1) (3 points total) Give an example of the following and circle the carbon.
a) An organic compound, which contains an sp-hybridized C.
b) An organic compound, which contains an sp 3 -hybridized C.
c) An organic compound, which contains an sp 2 -hybridized C.
2) (4 points total) Which of the following molecules can exist as cis/trans (E/Z) isomers?
Circle the compound, which do. If there is a stereogenic carbon, put a star on it.
(a) (CH3)HC=CHCH2CH2CH(CH3)CH2CH2OH
(b) (CH3)2C=CHCH2CH2C(CH3)=CHCHBrCH2OH
1

3) (7 points) Provide the following:
a) Give an example of an alcohol and name it.
b) Name the following bicyclic compound:
Cl
c) Give an example of a diol:
d) Give an example of an ether and name it:
4) (2 points) Circle the group, which is most acidic in the following compounds
HO
F Cl
OH
5) (1 point each/ total 3 points) What are the conjugate acids for the compounds below?
a) H2O b) NH3 c) CH3OH
6) (1 point each/ total 3 points) What are the conjugate bases for the compounds below?
a) H2O b) NH3 c) CH3OH
OH
SH
2

7) (1 point each/21 total points) For each statement, circle the most appropriate
word to make the statement correct.
a) The hydration reaction is the addition of H2O across the double bond in (acid, base, or
spaghetti)-catalyzed conditions.
b) The formula used to calculate the theoretical amount of stereoisomers is (2 n , nx + b, or
a 2 + n 2 ) where n is the number of chiral centers.
c) Pentahelicene is (achiral, chiral or meso) compound.
d) 2,3-Butadiene is (achiral, chiral or meso) compound.
e) Biphenyl is (achiral, chiral or meso) compound.
f) The torsional strain in planar cyclohexane is (higher, lower, or the same) than planar
cyclopentane.
g) The angle strain of cyclopropane is (higher, lower, or the same) than planar
cyclobutane.
h) The heat of formation in the standard states of cyclopentane is (more than, less than or
the same) than that of cyclohexane.
i) The heat of combustion in the standard states of cyclohexane is (more than, less than or
the same) than that of cyclopentane.
j) Cis 1,3-dimethylcyclohexane is (achiral, chiral or meso) compound.
3

k) One conformational stereoisomer of (S,S) trans-1,2-dichlorocyclohexane converts to
(RR; RS; SR; or SS) trans-1,2-dichlorocyclohexane via a chair flip.
l) The relationship between the chair interconversion of 1,1-dimethylcyclohexane is that
they are (conformational enantiomers, conformational diastereomers, or identical).
m) The relationship between the chair interconversion of cis-1,2-dimethylcyclohexane is
that they are (conformational enantiomers, conformational diastereomers, or identical).
n) The relationship between the chair interconversion of trans-1,2-dimethylcyclohexane
are that they are (conformational enantiomers, conformational diastereomers, or
identical).
o) The relationship between the chair interconversion of cis-1,3-dimethylcyclohexane are
that they are (conformational enantiomers, conformational diastereomers, or identical).
p) The relationship between the chair interconversion of trans-1,3-dimethylcyclohexane
are that they are (conformational enantiomers, conformational diastereomers, or
identical).
q) The relationship between the chair interconversion of cis-1,4-dimethylcyclohexane are
that they are (conformational enantiomers, conformational diastereomers, or identical).
r) The relationship between the chair interconversion of trans-1-isopropyl-2methylcyclohexane
are that they are (conformational enantiomers, conformational
diastereomers, or identical).
4

s) The relationship between the chair interconversion of trans-1,4-dimethylcyclohexane
are that they are (conformational enantiomers, conformational diastereomers, or
identical).
t) Homework for our course is due by 5 PM of (the same class period, the next class
period, or the next week) after we complete the chapter.
Short Answer (31 points) Answer all parts for the following reactions.
8) (10 points) Star the chiral (stereogenic centers) in the compound (cortisone) below.
Then, assign chirality (R or S) to each of those centers. Theoretically, how many possible
stereoisomers would there be for the structure below?
O
O
CH 3
H
H
O
CH 3
H
OH
OH
5

9) (21 points) For all of the following reaction, show all of the products (7 points each).
Note the stereochemistry (R/S and * the chiral centers) and major/minor product where
necessary. Also, pick one reaction and show the mechanism for the formation of the
products for the first reaction (7 points). If some part of your reaction is written in
another place, clearly indicate where. Circle all of your products.
b)
a)
1) H-Br
2) Mg, ether
3) D2O H 3O +
H 2O
6

Part III. Essay. (26 points)
10) (13 points) Draw all of the possible chair forms and stereoisomers of cis- and trans-
1-bromomethyl-2-chlorocyclohexane. State the relationships between isomers, state the
relationships between their flipped isomers, label R/S if applicable, and specify their
stability.
7

11) (13 points) Draw all of the possible chair forms and stereoisomers of cis- and trans-
1,3-diisopropylcyclohexane. State the relationships between isomers, state the
relationships between their flipped isomers, label R/S if applicable, and specify their
stability.
8