Cyclopropanation is the general name for a series of reactions that all produce very similar products by different mechanisms. You may be responsible for one or more of these reactions on your exam, so let’s get into them.
Concept #1: General properties of cyclopropanation.
Concept #2: Reaction with a simple carbene.
Concept #3: Reaction with chloroform (CHCl3) and tert-butoxide.
Concept #4: Reaction with diazomethane and light or heat.
Concept #5: The Simmons-Smith reaction.
You should not be responsible for the full mechanism of Simmons-Smith, but you should know what the reagents are, and be able to predict that it is a form of cyclopropanation.