OCHEM test 2

Enantiomers

mirror images. wedges and dashes get switched

stereoisomer possibilities formula

2^chiral centers

R

turns right

S

turns left

Constitutional isomers

different connections

Stereoisomers

same connections with different orientations of space

Polar aprotic solvents

DMF, THF, DMSO, dietherylether, acetone, acetonitrile (no OH or NH)

Polar protic solvents

R-OH

Halide stability

I (biggest, most stable), Br, Cl (smallest)

SN2 Rxn

1 step
Rate = k(R-LG)(Nuc)
Polar aprotic
Backside attack
WONT WORK IF 3 R GROUPS

exothermic

products lower than reactants

endothermic

products higher than reactants

SN1 rxn

2 step reaction
Rate = k(R-LG)
WONT WORK IF 1 R GROUP
Backside and Frontside attack
Polar protic

Stability of alkenes

The more R groups on the carbons the more stable
More stable if larger groups are trans

E2 rxn

1 step
Rate = k(base)(R-LG)

E1 rxn

2 step
Rate = k(R-LG)
Polar Protic
WONT WORK IF 1 R GROUP

Leaving group ability trend (SN rxns)

towards bottom right

Nucleophilicity trend (Polar aprotic)

towards bottom left

Nucleophilicity trend (Polar protic)

towards top left

Order or halogens (on table)

F, Cl, Br, I

Good nuc, not basic

R3N, N3, CN, X

Not good nuc/ not basic

R-OH

Good nuc, basic

HO, CH3O, alkoxides

Non-nuc bases (for E2)

DBU, DBN, t-buOK

enantimors (R,R)

opposites

Identical (R,R)

same (R,R)

Diastermors (R,S)

different on one (R,R)

Prioritizing (STEERING WHEEL)

Highest atomic number gets highest priority