Chemistry Reference
In-Depth Information
11.
Given a stereogenic center in a molecule, assign the
R
or
S configuration to it.
12.
Draw the three-dimensional formula of a molecule with a particular configuration,
R
or
S
.
13.
Given a pair of
cis-trans
isomers, assign the
E
or
Z
configuration.
14.
Draw the formula of an alkene with a particular configuration,
E
or
Z
.
15.
Given a structure with one or more stereogenic centers, draw a Fischer projection.
16.
Given Fischer projections of two isomers, tell their relationship (for example, same
structure, enantiomers, diastereomers).
17.
Assign
R
or
S
configuration to each stereogenic center in a Fischer projection.
18.
Given a structure with more than one stereogenic center, tell how many
stereoisomers are possible and draw the structure of each. Tell what relationship the
stereoisomers have to one another (for example, enantiomeric, diastereomeric).
19.
Tell whether a particular structure can exist as a
meso
form.
20.
Given a structure with two or more identical stereogenic centers, draw the structure
of the
meso
form.
21.
Given a pair of stereoisomers, classify them as configurational or conformational,
chiral or achiral, and enantiomers or diastereomers.
22.
Given a chemical reaction that gives a chiral product, tell the stereochemistry of the
products.
ANSWERS TO PROBLEMS
Problems Within the Chapter
5.1
a.
chiral
b.
achiral
c.
achiral
d.
chiral
e.
achiral
f.
chiral
g.
chiral
h.
achiral
The achiral objects (teacup, football, tennis racket, and pencil) can be used with
equal ease by right- or left-handed persons. Their mirror images are superimposable
on the objects themselves. On the other hand, a golf club must be either left- or right-
handed and is chiral; a shoe will fit a left or a right foot; a corkscrew may have a
right- or left-handed spiral. These objects, as well as a portrait, have mirror images
that are
not
identical with the objects themselves, and thus they are chiral.
5.2
The stereogenic centers are marked with an asterisk. Note that each stereogenic
center has four different groups attached.
a.
b.
H
*
CH
3
c.
d.
H
H
**
CH
3
C
C
CH
3
Br
Br
