CH 19 rxns

Question 1

Wolff Kishner Reduction

Answer 1

NH2NH2, KOH
-gets rid of C=O

Question 2

Enamine Formation

Answer 2

HNR2
-replaces C=O with enamine

Question 3

imine formation

Answer 3

RNH2
-in basic or neutral conditions
-replaces C=O with C=NR

Question 4

Protecting with acetal (cyclic)

Answer 4

HO-CH2-CH2-OH, pTSA
-replaces C=O with cyclic acetal

Question 5

Protecting with ketal

Answer 5

ROH, pTSA
-replaces C=O with ketal

Question 6

to introduce a new group on thioacetal

Answer 6

nBuLi to deprotonate H

Question 7

to go from acetal or ketal to carbonyl

Answer 7

H2So4, H20

Question 8

to get rid of thioacetal or thioketal back to alkane

Answer 8

H2
Raney Ni

Question 9

corey seebach

Answer 9

SH-CH2-CH2-SH, pTSA to add thioacetal
nBuLi to deprotonate H
- neg charge SN2 on e-phile
-go back to C=O with H2SO4, H20 or alkane with H2 and Raney Ni

Question 10

cyanohydrin formation

Answer 10

1)KCN
2)HCl, H20
-replaces C=O with -OH and -CN

Question 11

CN reactions

Answer 11

1)LAH
2)H20
-replaces N on CN w/ NH2 (Beta hydroxyamine)

Question 12

CN reactions

Answer 12

H2SO4, H20
-replaces C on CN w/ COOH (alpha hydroxycarboxylic acid)

Question 13

Wittig

Answer 13

Ph3P=R2
-staples two group from each = together
-creates 1 alkene from 2 molecules

Question 14

ylide with ketone

Answer 14

-creates C=C

Question 15

Baeyer-Villiger Oxidation

Answer 15

RCO3H
-inserts O into most subst. side of carbonyl

Question 16

T/F: ketones are more reactive to nuc attack than aldehydes

Answer 16

F

Question 17

hydrate formation

Answer 17

C=O + H20 gives hydrate/gemdiol

Question 18

for hydrate formation, equilibrium favors carbonyl under neutral conditions except for….

Answer 18

formaldehyde and EWGs

Question 19

when to protect aldehydes and ketones with acetals and ketals?

Answer 19

under strong basic or nuc conditions

Question 20

what is a ylide

Answer 20

dipolar intermediate with formal opposite charges on adjacent atoms

Question 21

the. wittig reaction is highly selective for?

Answer 21

ketones and aldehydes

Question 22

What groups will not react but are tolerated In the substrate with wittigs

Answer 22

esters, lactones (cyclic esters), nitriles, amides

Question 23

what groups are not tolerated with wittigs

Answer 23

alcs, amines, carboxylic acids

Question 24

what stereochem do wittigs favor when simple alkyl halies are the subst. on the wittig

Answer 24

Z

Question 25

what stereochem do wittigs favor when carbonyls or EWGs are subst. on the wittig

Answer 25

E

Question 26

For wittigs, what stereochem is for the thermodynamic product

Answer 26

E

Question 27

For wittigs, what stereochem is for the kinetic product

Answer 27

Z

Question 28

what reagent set oxidizes primary alc all the way to the carboxylic acid

Answer 28

Na2Cr2O7, H2SO4, H20

Question 29

for the Baeyer-Villiger oxidation, the group migration trends are?

Answer 29

H>3>2,Ph>1>methyl