Chapter 18

Question 1

Acid-catalyzed synthesis of ethers

Answer 1

Sn2, only for primary, see notes for mechanism

Question 2

Williamson Ether Synthesis

Answer 2

Sn2
1) NaH, THF 2) RI
1) RI, Ag2O
(make it so that R in RI is as non-bulky as possible)

Question 3

Alkoxymercuration of Alkenes

Answer 3

1) (CF3CO2)2Hg, CH3Ch2OH

2) NaBH4

Question 4

Acid Cleavage of Ethers (Cases)

Answer 4

only primary and secondary substituents: Sn2

tertiary, benzylic, allylic: Sn1 (most stable intermed)

Question 5

Acid Cleavage of Ethers (reagents)

Answer 5

H(I or Br), H2O, reflux->subs

CF3CO2H, 0C

Question 6

When to use Williamson Ether or Alkoxymercuration

Answer 6

WE: HX is primary or methyl (2 or 3 does E2)
Alkoxy: ROH is primary, sec, or tert (can’t make ditert ether)

Question 7

names of ether rings (2C, 4C, 5C)

Answer 7

ethylene oxide, tetrahydrofuran, tetrahydropyran

Question 8

name of 4C ether ring, 2 O’s at each end

Answer 8

1,4-dioxane

Question 9

Claisen Rearrangements

Answer 9

happens with ally aryl ethers and allyl vinyl ethers