This track is a consolidation rather than new content, designed to drill the "predict-the-product / propose-the-mechanism" skill across everything in Orgo 1 and the first half of Orgo 2.

The reprise pulls together the recurring decision framework that runs through the whole course:

Identify the players. Label the nucleophile/base, the electrophile, and the leaving group in every problem (Track 16). Nearly every mechanism reduces to electron-rich attacking electron-poor.
Ask the four diagnostic questions for substitution/elimination (Track 15): substrate class (1°/2°/3°), nucleophile vs. base strength, leaving-group quality, and solvent — then decide SN1/SN2/E1/E2. Add heat → favor elimination.
Watch for carbocations. Whenever a carbocation forms (SN1, E1, Markovnikov additions, acid-catalyzed alcohol reactions), check for rearrangements and expect racemization at the reacting center.
Track stereochemistry deliberately: SN2 → inversion; bridged intermediates and epoxide opening → anti; concerted additions (hydrogenation, hydroboration, syn-dihydroxylation) → syn.
Push arrows correctly. Every mechanism is just electrons moving from high density (lone pair, pi bond, sigma bond) to low density; drawing valid arrows is the single habit that most improves mechanism scores.

Practicing with this checklist — rather than memorizing individual reactions — is what converts two semesters of scattered reagents into a coherent, predictive system. From carbon's four bonds in Track 1 to the code molecules of Track 45, every mechanism in this guide reduces to the same handful of moves: identify the nucleophile and the electrophile, push the arrows from electron-rich to electron-poor, and track the stereochemistry the mechanism demands. That is the whole map.

"The Whole Map"