OCHEM 2 Synthesis Reagents

NaH

Creates a good leaving group

HCl + H2O

Alcohol to good leaving group

POCl3 + Pyridine

Elimination at most substituted carbon near alcohol (Zaitzev’s Rule)

H2SO4

Elimination, forms double bond at most substituted carbon in molecule due to carbocation (+) formation

HBr

Alcohol to good leaving group; if alcohol on non-primary Carbon, carbocation rearrangement

PBr3

Inversion, substitution of good leaving group

SOCl2

Inversion, substitution of good leaving group

TsCl + Et3N

No inversion, addition of good leaving group (OTs)

HBr + Ether

Ether cleavage —> Br Addition on larger side + small side alcohol

Epoxides (Acid)

Inversion alcohol addition at more sub carbon

Epoxides (Strong Nu-)

Inversion alcohol addition at less sub carbon

H2SO4 + H2O (Alkene)

Alcohol addition at must substituted carbon

HBr (Alkene)

Br addition at most substituted carbon

HCl + H2O (Alkene)

Alcohol addition at most substituted carbon

Ts-OH (Alkene)

OTs addition at most substituted carbon

Br2 (Alkene)

Dibromide due to Ketone-like Br initial addition

Br2 + H2O (Alkene)

Br addition at least substituted carbon, Alcohol addition at most substituted carbon

BH3 (Alkene)

B + 3 Alkane extension (Anti-Markovnikov)

1. BH3

2. H2O2 + NaOH

(Alkene)

Alcohol addition at less substituted carbon (Anti-Markovnikov); selectivity = opposite adjacent R group

HBr (Alkyne)

2 Br at most substituted carbon

H2SO4 + HgSO4 + H2O (Alkyne)

Ketone at most substituted Carbon

1. BH3

2. H2O2, NaOH

(Alkyne)

Ketone at least substituted carbon (Anti-Markovnikov)

Ph Group 1. BH3 2. H2O2 + NaOH

Ketone at must substituted carbons (multiple products)

Br2 (Alkyne)

Dibromide at each triple bond terminus

Br2 Intermediate (Alkyne)

Single Br addition at each triple bond terminus

NaNH2 × 3

Alkyne Synthesis (Strong Nucleophile)

1. Br2

2. NaNH2 × 3

3. H2O

(Alkene)

Alkyne with H end synthesis