[Organic Chemistry] Addition reactions of alkenes

$\star$ addition $\leftrightarrow$ elimination : 역반응

Hydrohalogenation

• reaction condition
  HX (X=Cl, Br, I) (-30°C)
• regioselectivity
  $-$ Markovnikov major ($\because$ Hammond postulate: late TS)
  $-$ Anti-Markovnikov major: HBr, phOOph (radical reaction)
  $-$ case1) 반응으로 chiral center 생성: Markovnikov's product, enantiomers
  $-$ case2) diastereomer 생성 (racemate)

• $C^+$ rearrangement

Hydration

hydration in acidic aqueous solution

• reaction condition
  $H_2SO_4(aq)$
• Markovnikov's product major
• $C^+$ rearrangement
• 단점: Markovnikov, $C^+$ 재배열만 생성가능

• 만약 c-$H_2SO_4$ 사용하면 반응 안감.
  alkene에 묽은 황산 사용하면 electrophilic addition reaction,
  alkane에 진한 황산 사용하면 elimination reaction.