SN1, SN2, SNi mechanisms
Haloalkanes and Haloarenes · Chemistry
Study notes
(CH₃)₃CBr + OH⁻ gives racemic product; CH₃Br gives inverted. Explain. Step 1: (CH₃)₃CBr: 3° → SN1; carbocation planar → OH⁻ attacks both faces → racemic mixture. Step 2: CH₃Br: 1° → SN2; backside attack → Walden inversion (configuration flips). Step 3: Stereochemistry diagnoses the mechanism! Step 4: Rule: racemization = SN1; inversion = SN2; retention = SNi.