chapter 9 - alcohol, ether, epoxide rxns

Question 1

dehydration rxns that form alkenes and H2O:
1.
2.

Answer 1

1. strong acids: H2SO4 or TsOH

2. POCL3/Pyridine

Question 2

SOCL2/Pyridine and PBr3 are always what mechanism?

Answer 2

SN2
1 degree and 2 degree

SOCl2 –> R-Cl
PBr3 –> R-Br

Question 3

POCL3/Pyridine is always what mechanism?

Answer 3

E2
1 degree and 2 degree
no carbocation rearrangement!

Question 4

Big bulky bases:

Answer 4

Na+-OtButyl
DBU
DBN

Question 5

R-OH

Answer 5

1. R-X (Cl, Br, I) = SN2

2. strong acid = E2

Question 6

R2-OH and R3-OH

Answer 6

1. R-X = SN1

2. Strong acid = E1

Question 7

Tosylate: TsCl/Pyridine

Answer 7

makes R-OTs (good LG):

1. strong nuc = SN2
2. big bulky base = E2

Question 8

alkene synthesis

Answer 8

E2
uses strong base:
NaNH2 or KOC(CH3)3/DMSO (solvent)

Question 9

rxn with tosyl chloride to form alkyl tosylates

Answer 9

Cl atom is the LG and R-OH bonds to molecule. looses H

Question 10

ethers

Answer 10

• 2 equivalents (Br or I)
  R-X + R-X + H2O

2 degree and 3 degree = SN1
CH3 and 1 degree = SN2

Question 11

epoxides

Answer 11

• backside attack forms anti or trans products
• Strong nuc = SN2 and nuc attack on less sub C
• H-Nuc = substitution and nuc attack occurs on more sub C