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as part of the data about a reaction. Maps are used
during searching to resolve certain types of
structure search hits.
Consider a simple esterification reaction:
O
OH
OH
Does the ester oxygen come from the acid or the
alcohol? You specify the fate of individual atoms
through an atom-to-atom map. In reality, the ester
oxygen in this reaction originates in the alcohol, so
the atom-to-atom map looks like this:
O
O
H 2 O
NOTE: For information about specifying atom-to-atom
maps with ChemDraw, see the ChemDraw User’s Guide.
Searching for Reactants
If you know what starting materials you are
interested in but don’t know their products, you
might perform a reactants query. A reactants query
is very similar to a reaction search, except that there
is nothing to the right of the arrow. For example,
consider the query:
O
1
3
O
Rxn
2
OH 4
5
OH 6 1
By matching numbers across the arrow, you can see
where atoms move during the course of the
reaction. The other reaction (not observed
experimentally), where the ester oxygen comes
from the acid, would be mapped like this:
1
3
O
2
OH 4
5
Rxn OH 6
2
Rxn O
6
ChemFinder uses atom-to-atom map information
to determine reacting centers for reactions. If only
some atoms are mapped, ChemFinder uses that
information and does not worry about the specific
fates of the other atoms. For example, if you don’t
know (or don’t care) about the mapping of some
atoms, you can leave them unspecified in the atomto-atom
map.
By default, atom-to-atom mapping is not displayed
within ChemFinder. To turn on this display, select
Atom-to-Atom Map on the Structure sub-menu
of the View menu. For more information, see
“Setting Preferences” on page 341.
1
3
O
3
O
2
O Rxn
4
5
5
H 2 O 4
H 2 O 6
O
O
If you are doing a substructure search, this finds any
reactions in which maleic anhydride or a compound
containing a maleic anhydride substructure is
consumed or transformed.
Searching for Products
If you know the desired end product but not how
to get there, you can do a products query. A
products query is similar to a reaction search,
except that there is nothing to the left of the arrow.
For example, consider the query:
If you are doing a substructure search, this finds any
reactions in which bicyclo[2.2.1]heptane or a
compound containing this substructure is
produced.
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Reaction Searches