exam 3 - addition rxns

Question 1

hydrohalogenation

Answer 1

• mechanism 1
• rxns of alkenes w/ HBr, HCl, HI

Question 2

hydration

Answer 2

• mechanism 1
• alkene + alcohol (ROH) + catalytic acid

Question 3

halogenation

Answer 3

• mechanism 2
  Reagents: X2, Br2, Cl-I, etc.
  Regiochemistry: N/A
  Stereochemistry: Anti only (trans)

Question 4

halohydrin formation

Answer 4

• mechanism 2
• X2 + R-OH (R = alkyl or H)

Question 5

hydroboration

Answer 5

• mechanism 3

Question 6

mechanism 1

Answer 6

1. proton adds to form C+
2. nucleophile adds to C+
   - stereoselectivity: syn + anti products (doesn’t matter because planar SM)
   - regioselectivity: Markovnik

Question 7

mechanism 2

Answer 7

1. electrophile adds to form 3-membered cyclic INTERMEDIATE
2. nucleophile is added from opposite side of electrophile
   - stereoselectivity: ANTI products
   - regioselectivity: nucleophile adds to side that best stabilizes delta positive charge

Question 8

mechanism 3

Answer 8

1. two groups that are connected to each other add simultaneously to alkene
   - stereoselectivity: SYN products
   - regioselectivity: matching delta + and delta - or based on size (