organic 2

Question 1

are ketones or enols favoured + why

Answer 1

ketones

C-H bond and C=O bonds are stronger than C=C and O-H

Question 2

enol

Answer 2

C=C - OH

Question 3

ketone and water

Answer 3

hydrate == gemdiolke

Question 4

ketone + alcohol

Answer 4

acetal

Question 5

ketone + CN-

Answer 5

cyanohydrin

Question 6

ketone + amine

then product + NaBH4

Answer 6

immine

then amine

Question 7

alpha proton

Answer 7

protons on C adjacent to C=O

Question 8

ketone to enol form

Answer 8

tautomerisationnnn

10^-7 Keq

Question 9

ketone and enols areee

Answer 9

tautomers

Question 10

are ketons or enols preferred

Answer 10

ketones

the individual bond strengthd are stronger.

Question 11

going from carbonyl to an enol is an example of what

Answer 11

an intramolecular proton transfer.

the less acidic // stable the H is,, the less likely tautomerisation will occur.

Question 12

are enols formed from ketones only

Answer 12

nopeee

carbonyls too

aka aldehydes and esters can also form enolssss

bc enol is just the c=c - OH formed by losing an alpha H+.

Question 13

aldehyde or enol

Answer 13

aldehyde favoured

Question 14

ester or enol

Answer 14

ester favoured but not as much as an aldehyde

bc EDG makes C more partially negative,, so the H e- arent really wanted.

Question 15

diketone or enol

Answer 15

enolllll

the O-H - - - O-

HYDROGEN BONDINGG

which stabilises the molecule.

and the system itself is conjugated making it more stable

Question 16

cyclic ketone or enol

Answer 16

enol

bc the tautomer is a phenollllll

which is highly favoured DUE TO AROMATICITY

Question 17

O-H - - - - O- meaning between carbonyls

Answer 17

hydrogen bonding
very strong ]very stabilising

Question 18

base and ketone give rise to what

Answer 18

• on the C u remove the alpha H’s from
• on the O u resonate the e- to. (enolate formed)

the O loves the - more!!!!
so u start the aroow and attack nucs from there.

Question 19

which enolate form can be used to react with nucs

Answer 19

borh

but from C is preferred

Question 20

attack from alpha C- to nucleophile issss

Answer 20

orbital overlap

soft

-c - c=o

Question 21

attack from O- to nucleophile isss

Answer 21

hard
charges and electrostatic interactions.

Question 22

what is pka of alpha Hs dependent on

Answer 22

groups next to it
fg next to the C=O
resonanance forms

Question 23

larger pka means

Answer 23

less acidic proton
more stable proton

Question 24

acetaldehyde + its alpha h pka

Answer 24

Ch3 - c=o - h

13.5

Question 25

acetone and its pka

Answer 25

Ch3 c=o Ch3

ch3 on other side donates to C=o via induction,, C is more p- so doesnt rlly want the H e-

so H is more stable

more stable. = more pka

so 20

Question 26

ethyl acetate and ph

Answer 26

CH3 - C=O - OEt

OEt : donates towards c=o

c is less positive
doesnt rlly want the H’s e-
H is more stable,, higher pka,, less acidic

25

Question 27

what is an aldol reaction

Answer 27

where aldehydes and ketones react and join to give

B-hydroxy aldehydes // ketones

Question 28

whats needed for an aldol reaction

Answer 28

base

to remove the alpha H

Question 29

aldol condensation conditions and product

Answer 29

strong acid/ base + heat

aldehyde + aldehyde –> aldol ,, then remove H20 to give a double bond and a c=o

Question 30

explain base catalysed aldol condensation

Answer 30

remove alpha proton from one of the molcules and resonate this up to the O to give O- and a double bond.

O- reforms c=o and double bond used to attack other carbonyl,, move e- to the o –> o-.

protonate the o- to give OH.

remove alpha protons and resonate the e- to the o –> o- and a double bond.

from o- to double to kick off OH.

Question 31

what is eneded inn a base catalysed aldol condensation and why

Answer 31

high heat and conc base

bc OH is a bad LG

E1cb elimination

Question 32

acid catalysed aldol condensation (removing H2o)

Answer 32

o on c=o bonds to H,, turns into O+ - H

alpha hydrogen is removed and O is neutralised, but double bond is formed. and O+ - H

other carbonyl is hydrogeneated - C =O+ - H

O: from carbonyl to double bond attacks the C=o of the other molecule and neutralises O.

OH binds to H from O+ -H and neutralises O. ,, h2o is formed

alpha protons are attcked and H20 is removed

Question 33

carbonyl and base

Answer 33

make an enolate

make the enolate c=c-o-
attack the other thing.

make sure u draw the arrow all the way to smt good and change the charge after.