carbonyl containing compounds/benzylic allylic position reactivity

Question 1

how to put a Br on the benzylic postion

Answer 1

Br2 or NBS, hv; radical boration mechanism

Question 2

carboxylic acid to an alcohol

Answer 2

1) LiAlH4
2) H3O+/H2O

Question 3

carboxylic acid to carbonyl

Answer 3

decarboxylation; carbonyl group beta to the carboxylic acid
conditions: H30+/H2O

Question 4

acid anhydride synthesis

Answer 4

2 equ of carboxylic acid + heat

Question 5

carboxylic acid to acid chlorides

Answer 5

SOCl2 or PCl5

Question 6

carboxylic acid to esters

Answer 6

• fisher esterification: alcohol and cat H2SO4 (fully reversable)

-Sn2: 1)base to deprotonate (NaHCO3) 2) X-alkyl group for Sn2

-Sn2 with diazomethane: CH2N2

Question 7

primary alcohol to carboxylic acid

Answer 7

CrO3, H2So4, H2O

Question 8

alcohol or alkyl group on benzene to carboxylic acid

Answer 8

1) KMnO4, OH- (aq), heat
2) H3O+/H2O

Question 9

aldehyde to carboxylic acid

Answer 9

1)NaOH, Ag2O, H2O
2) H3O+/H2O

Question 10

bromine attached to a benzene -> carboxylic acid

Answer 10

1) Mg/ Et2O
2) CO2
3) H3O+/H2O

Question 11

C=O to C=C

Answer 11

Wittig reaction:

1)PPh3
2) nbutLi (strong base to deprotonate carbon)
3) 2RC-PPh3 reacted with C=O

Question 12

aldehyde/ketone to alkane (reduction)

Answer 12

basic conditions: Wolff-Kishner reduction
H2N-NH2, OH-, heat, triethylene glycol
acidic conditions: clemmensen reduction
ZnHg, HCl, EtOH, heat

Question 13

carbonyl to imine

Answer 13

primary amine

Question 14

carbonyl to enamine

Answer 14

secondary amine

Question 15

ketone to acetal (protecting group)

Answer 15

diol and acid (H2SO4)

Question 16

carbonyl to hemiacetal to acetal

Answer 16

alcohol excess

Question 17

acetal to hemiacetal to ketone

Answer 17

H2O excess

Question 18

reduction of carbonyls to alcohols

Answer 18

• NaBH4 and H2O or alcohol
• 1)LiAlH4/ether (aprotic solvent) 2)mild H+/H2O

-H2, Ni, 102 atm, 120 C

*secondary alcohols

Question 19

ketone to hydrate/ gen diol

Answer 19

excess H2O

Question 20

phenol to quinone

Answer 20

Na2Cr2O7, H2SO4 (aq); Cr reagent

Question 21

phenol to tribrominated benzene

Answer 21

Br2 (excess) H2O

Question 21

phenol to dibrominated benzene

Answer 21

Br2 (excess) H2O, HBr

Question 22

phenol to monobrominated benzene

Answer 22

Br2 (1 equ), CCl4

Question 23

aryl halid organometallic coupling rections

Answer 23

form new C-C sigma bond;
heck: vinylic H on alkene
suzuki: boronic acid on ring (B(OH)2)

Question 24

how to put boronic acid on a ring

Answer 24

1) Br2, FeBr3
2) Mg/ EtO
3) B(OH)2
4) H2O/H3O+

Question 25

substitution reaction on an aryl halide

Answer 25

SnAr: Nucleophilic attack -> negative intermediate (lone pair ) -> leaving group halide leaves

**must have EWG on ring to stabilize intermediate

Question 26

elimination (E2) reaction on aryl halide

Answer 26

strong base -> benzyne intermediate -> substituted ring with strong base