Teaching approaches to overcome thresholds in A level organic chemistry

Over many years of teaching A level Chemistry we have become aware of the difficulties students have with learning organic chemistry. We have summarised these issues as a series of “Threshold Concepts” that students must overcome before they can go on to understand more complex aspects of organic chemistry. These thresholds include a) Molecules are dynamic and not static as drawn on paper; b) Any drawing on paper is a 2D representation of a 3D molecule, and the same structure can be drawn differently; c) Reactions often occur only at a particular location(s) in an organic molecule d) Reactions happen in a series of steps, where the order of events matters and e) Reactions involve the movement / redistribution of electrons. We have developed a new teaching sequence and resources to help students progress towards passing these thresholds and develop connections between different groups of organic compounds.