2x bond reactions

Role of Electrons: Electrons are needed for the power of anions, influencing reaction mechanisms.
Cathionic Reactions: HBr can initiate reactions through cationic mechanisms, sometimes involving peroxide.
Boron Compounds: BH3 can release H+, influencing carbocation formation without breaking homolytically like in reactions with light and HBr.

Mechanism Variability: Different conditions (like light or peroxide) affect the formation of intermediates in reactions.
Bridged Intermediates: Formation of bromonium ions is a key step, where bromine interacts through a backside attack.
Thin Addition: Important concept involving the addition of reagents to alkenes resulting in concerted reactions, without forming different orientations (two wedges or two dashes).
Epoxidation: Similar to rhodium-catalyzed reactions, epoxidation involves creating a three-membered ring, stabilizing the reaction intermediate.

Flashcard Method: Write down molecule and conditions on one side of a flashcard and products on the other, indicating addition types (e.g., thin addition).
Reaction Visualization: Draw molecular structures carefully to indicate stereo-specific impacts, especially around double bonds and chiral centers.
Practice Mechanisms: Familiarity with reaction steps and types is critical, though not every mechanism needs to be memorized.