chapter 8 Flashcards
1
Q
E2
A
- one step
- second order kinetics
- 3 > 2 > 1
- rate = k[RX][B]
- anti periplanar arrangement of H and X
- favored by strong bases
- better LG = faster rxn
- aprotic solvents
- more substituted alkene favored
2
Q
E1
A
- two steps
- 3 > 2 > 1
- rate = k[RX]
- first order kinetics
- trigonal planar carbocation
- favored by weaker bases
- better LG = faster rxn
- protic solvent favored
- more substituted alkene favored
- CAN DO A SHIFT
3
Q
1 degree
2 degree
3 degree
A
1 degree:
- strong nuc = SN2
- big bulky base = E2
2 degree:
- strong base and nuc = E2 + SN2
- strong bulky base = E2
- weak base and nuc = E1 + SN1
3 degree:
- weak base and nuc = E1 + SN1
- strong bulky base = E2
4
Q
Do E1 and E2 have the same 1st step?
A
yes
5
Q
alpha C vs beta C
A
alpha - bonded to LG
beta -adjacent to alpha C
6
Q
sterochemistry for elimination
A
- syn and anti periplanar arrangements
- trans alkenes most stable
- whenever 2 groups are different on each end of c=c, two diastereomers are possible (cis and trans)
- ***** E2: halocyclohexanes prefer trans diaxial gemometry! Wants less stable conformation. Cl and H must be axial
7
Q
vicinal dihalide vs geminial dihalide
A
vicinal - X atoms on adjacent C
geminial - X atoms on same C
