chapter 9 - alcohol, ether, epoxide rxns Flashcards
1
Q
dehydration rxns that form alkenes and H2O:
1.
2.
A
- strong acids: H2SO4 or TsOH
2. POCL3/Pyridine
2
Q
SOCL2/Pyridine and PBr3 are always what mechanism?
A
SN2
1 degree and 2 degree
SOCl2 –> R-Cl
PBr3 –> R-Br
3
Q
POCL3/Pyridine is always what mechanism?
A
E2
1 degree and 2 degree
no carbocation rearrangement!
4
Q
Big bulky bases:
A
Na+-OtButyl
DBU
DBN
5
Q
R-OH
A
- R-X (Cl, Br, I) = SN2
2. strong acid = E2
6
Q
R2-OH and R3-OH
A
- R-X = SN1
2. Strong acid = E1
7
Q
Tosylate: TsCl/Pyridine
A
makes R-OTs (good LG):
- strong nuc = SN2
- big bulky base = E2
8
Q
alkene synthesis
A
E2
uses strong base:
NaNH2 or KOC(CH3)3/DMSO (solvent)
9
Q
rxn with tosyl chloride to form alkyl tosylates
A
Cl atom is the LG and R-OH bonds to molecule. looses H
10
Q
ethers
A
- 2 equivalents (Br or I)
R-X + R-X + H2O
2 degree and 3 degree = SN1
CH3 and 1 degree = SN2
11
Q
epoxides
A
- 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