Three-Dimensional Representations: Cyclic Wedge-Dash Notation
Wedge-Dash Notation is also commonly used for cyclic systems. As with straight chains, cyclic
Wedge-Dash Notation has two bonds drawn in the plane of the page (
sticks), one bond drawn coming toward you, out of the page and above the ring (
wedged), and one bond drawn going away from you, behind the page and below the ring (
dashed). It is important to note that groups with the same orientation (both
wedged or both
dashed) are
cis to one another, and groups with opposite orientations (one
wedged and one
dashed) are
trans to one another.
In the structure above, the methyl group is behind the page. Since there must be four bonds to each carbon, and two
sticks and one
dash have already been drawn in, the remaining hydrogen must be
wedged.
A similar analysis can be done for the carbons with the alcohol and the bromine. What is the orientation of the remaining hydrogens on these carbons?
Both the alcohol and the bromine are coming out of the page. For both groups, two
sticks and one
wedge have already been drawn in, so the remaining hydrogens must be
dashed.
More examples
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