Draw Mirror Images

Introduction:

When deciding if two groups are stereoisomers or the same, you need to answer the question whether the two molecules are mirror images.  One way to do this is to draw the mirror image of the first molecule and see if it is the same as the second.

How to:

When deciding if two groups are stereoisomers or the same, you need to answer the question whether the two molecules are mirror images.  One way to do this is to draw the mirror image of the first molecule and see if it is the same as the second.

Mirror below: All the atoms will stay in the same place but any stereocenter (up or down group) will be flipped.

Mirror mirror to one side: The atoms will be flipped.  Groups on the left will be on the right (and visa versa).  However, all the stereocenters will stay the same.

Comment:  In the above examples, the mirror image is different from the original molecule.  This means that each molecule is chiral.  The relationship between the original molecule and its mirror image are enantiomers.