Epoxide Opening with Acids, Bases and Grignards

Posted on December 7th, 2012

We here at StudyOrgo.com think it is very important to help students make connections when studying organic chemistry. When professors teach you about reactions, or you read a textbook about isolated reactions, one rarely picks up the underlying connection between related reactions. One reason that professors do not teach you these things is because it becomes a highly-testable concept that you have to “figure out on your own.” One of our main goals is to identify key connections and present them for you throughout our materials.

Take, the opening of an epoxide as an example. The reagent will attack an epoxide at varying parts of the substance depending on the type of reagent. For example, acids attack the most substituted position on the epoxide, bases attack the least substituted position and grignards also attack the least substituted position.

So here it is in plain, simple English:

  • Acid catalyzed epoxide ring opening: attack the most substituted position on the epoxide.
  • Base catalyzed epoxide ring opening: attack the least substituted position on the epoxide.
  • Grignard epoxide opening: attack the least substituted position on the epoxide

To review these key concepts with reaction examples, visit our reaction flashcard “Study Mode” (members only) which can be accessed from the account homepage.


1) Epoxides category- Epoxide Opening Reactions (7 reactions)

2) Alcohols category – Grignard Epoxide Opening Reaction

Then practice by creating your own custom quizzes by visiting our “Quiz Mode” homepage (members only also).