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132 CHAPTER 5 
 
Common Mistakes to Avoid 
 
When drawing a chiral center, the four groups connected to the chiral center must be drawn so that one 
group is on a wedge (which indicates that it is coming out of the page), and one group is on a dash (which 
indicates that it is going behind the page), and two groups are on straight lines (which indicate that these 
two groups are in the plane of the page), as seen in each of the following drawings: 
 
 
 
Notice that in all of these cases, the two straight lines form a V, and neither the dash nor the wedge is 
placed inside that V. This is very important. If either the dash or the wedge is placed inside the V, the 
drawing becomes ambiguous and inaccurate. Don’t make this mistake, as it is a common mistake: 
 
WRONG
This dash cannot
be placed here,
inside the V
This wedge cannot
be placed here,
inside the V
WRONG
 
 
The drawings above do not make any sense, and if a chiral center is drawn like either of the drawings 
above, it would be impossible to assign a configuration to the chiral center. Never draw a chiral center that 
way. For the same reason, never draw a chiral center like this: 
 
 
 
These two drawings imply square planar geometry, which is not the case for an sp3 hybridized carbon atom 
(the geometry is tetrahedral). In some rare cases, you might find a chiral center for which three of the lines 
are drawn as straight lines, as in the following example: 
 
 
 
This compound has one chiral center, and its configuration is unambiguous (and therefore acceptable), 
although you will not encounter this convention often. In most cases that you will encounter in this course, 
a chiral center will be drawn as two lines (making a V), and one wedge and one dash that are both outside 
of the V: 
 
 
 
 
 
 
 
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