The chemical theory of organic chemistry is largely based on electron patterns. Patterns are represented by Lewis structures, and changes in patterns are represented by curved arrows.
A change in electron pattern can be due to a chemical reaction:
or electron delocalization (resonance):
These examples are so simple, you might wonder why I am making a big thing out of curved arrows. It turns out (and you have to take my word for this) that curved arrows are an extraordinarily powerful mental tool. Curved arrows make it easier to describe and understand chemistry, learn new chemistry, forge connections between seemingly unrelated chemical phenomena, and predict exciting new kinds of chemistry. You might almost say that organic chemists think in curved arrows.
I can't emphasize the helpfulness of
curved arrows enough. I also can't emphasize enough the fact that you need to practice drawing curved arrows (and Lewis structures) if you are going to benefit from them. I suggest that, as you begin your studies, every time you work on a molecule, you draw its Lewis structure and any curved arrows that might apply.
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