Chem 210 – Reactions Questions 100% Answered!

Reagent = Nucleophile Only - ANSWER1° = Sn2 2° = Sn2 3° = Sn1 + E1 (polar medium necessary) Reagent = Strong Nucleophile & Strong Base - ANSWER1° = Sn2 2° = E2 3° = E2 Reagent = Weak Nucleophile and Weak Base - ANSWER1°/2° = No Reaction 3°/resonance stabilized carbocation = Sn1 + E1 (polar medium necessry Reagent = Base Only - ANSWER1° = E2 or Sn2 (if unhindered and no beta-hydrogen with unhindered base) 2° = E2 3° = E2 Examples of Only Nucleophiles - ANSWERCl⁻, Br⁻, I⁻, N₃⁻, CN⁻, HS⁻, RS⁻, RCO₂, R₃P, R₂N, RSH, H₂S Examples of Strong Nucleophiles and Strong Bases - ANSWERHO⁻, H₂CO⁻, H₃CH₂CO⁻ Examples of Weak Nucleophiles and Weak Bases - ANSWERH₂O, R-OH, RCO₂H Examples of Bases Only - ANSWER- strong bases with pKa of conj. acids > 30 - Hindered bases with pKa of conj. acids > 10 DBU H⁻ CH₃CO⁻ Mechanism I of Addition Reactions to Alkenes - ANSWERProton (H⁺) add to alkene to form carbocation Nucleophile then adds to carbocation Stereoselectivity: syn + anti products Regioselectivity: Markovnik (more stable carbocation) Mechanism II of Addition Reactions to Alkenes - ANSWERElectrophile (E⁺) add to form 3-membered cyclic intermediate from top and bottom Nucleophile adds to carbocation from opposite side of E⁺ Stereoselec