organic 1

Question 1

the carbonyl O is aaaaa

and what does this mean

Answer 1

weak base

means it can use its lone pair to attack a H+. it donates its lone pair

Question 2

lewis acid

Answer 2

accepts

accepts electrons

Question 3

lewis base

Answer 3

donates

donates electrons - its lone pair

Question 4

alpha protons

Answer 4

the H’s on the carbon adjacent to the carbonyl

Question 5

when can we add things directly to the carbonyl

Answer 5

when we resonate the double bond on C=O onto the O to give +C—O-

arrow from double bond to the O. makes C positive

Question 6

how do we form a cyanohydrin and what does it look like

Answer 6

cyanohydrin = R R C OH CN

ester + CN- —> CN attacks the C,, arrow to O,, then O- acts as a base and attacks a H,, to give OH.

H3O+ can be used as a H donator. - forms water and cyanohydrin

Question 7

at what angle should a nuc attack the C of a carbonyl (C=O)

Answer 7

at 107*

the burgi dunitz trajectory

into the LUMO

think butterfly,, 2 out the O and 2 larger ones out the C,, we draw arrow from NUC to 1/2 of the ones by the C.

from the nucs homo,, to the carbonyls lumoooo.

Question 8

how do we normally draw the order of a nucleaophile attacking a carbonyl

Answer 8

the nuc attacks the C

move the e- from the double bond to the O and give the O- a negative charge.

Question 9

why is the nuc attracted to the C of the carbonyl

Answer 9

bc O is more electronegative so there is a partial negative on the O and partial positive on the C.

Question 10

how do we form a hydrate // gemdiol

Answer 10

take a ester

use H2O as the nuc and attack the C of ther carbonyl,,

move e- to the O-.

use the lone pair on O to attack a H+ to give R R C OH OH

Question 11

if theres an electron withdrawing group on the C of the carbonyl,, what do we do

Answer 11

we use the O as a base and use its lone pairs to attack a H+.

before we attack the C.

Question 12

describe an acetal

Answer 12

R R C OR OR

Question 13

diff between gemdiol // hydrate and acetal

Answer 13

gemdiol // hydrate = R R C OH OH

acetal: R R C OR OR

Question 14

how do we make an acetal

Answer 14

R R C O ( ketone)

O attacks a H
O becomes +
HOR attacks the C and e- go to O,, to neutralise it.

H e- go to the OR so H can be removed. R R OH OR

OH attacks a H to become H2O,, lone pair on O on OR is used to make a double bond and kick of water.

C=O+ - R is what we get

then another HOR is used to attck the C of the carbonyl.

and then its deprotonated to give R R C OR OR an acetal

Question 15

how can we speed up the acetal synthesis when we use a ketone and alcohols,, HOR’s

Answer 15

add more acid: adds more H+ to it!!

remove water to prevent the back reaction from forming,, bc water is lost and the arrows are reversible.

Question 16

how can we remove water from things to prevent their back reactions from occurring and to speed up reactions

Answer 16

we use seives

drying agents like magnesium sulfate

Question 17

whats an imine

Answer 17

R R = N R

Question 18

how do we form an imine

Answer 18

ester is attacked by amine - lone pair on N.

e- in = are moved to the O to give O-.

O- steals the H from the amine

this neutralises N and O

then the OH attacks a H+ to form water.

the lone pair on the N is used to remove water

the H is removed from the N+,, an imine is formed,, R R = N - R

Question 19

the C on a carbonyl is aaaa

Answer 19

electrophile

Question 20

lumo on carbonyl, where homo e- go

Answer 20

pi star orbital

pi antibonding orbital

Question 21

what does an EWG on the C dooo

Answer 21

makes C more positive,,, more electrophilic.

more reactive to electrophiles.

makes electrophilic addition more favourable.

bc it takes away e- density from the C =,, giving it a more partial positive character.

Question 22

name a source for H+ in acetal synthesis

Answer 22

H2SO4
TsOH

Question 23

are aldehydes or ketones more reactive to electrophilic addition

Answer 23

aldehydessssss

bc H doesnrt donate electron density via inductive effect

ketones have R groups which donate e- density to the C making it less partially positive,, more partially negative and less likely that a nucleophile will attack.

Question 24

whats more electrophilic,, ketones or aldehydes

Answer 24

aldehydes

Question 25

alkyl groups areee

Answer 25

electron donatingggg

inductive effect

Question 26

imine to amine is calledddd

Answer 26

reductive amination
gain of hydrogen so reduction

from double to single bond

Question 27

explain reductive amination

Answer 27

imine R R C = N R

+Na -BH3 (CN) is used :e- from B-H bond attacks the C,, e- from = go to the N

N becomes N -

N- attacks a H+

R R C N R H amine is formed

Question 28

why is Na(CN)BH3 used in reductive amination

Answer 28

bc it gives -BH3

and its a milder hydride donor than NaBH4 due to CN being an EWG.

this means it only reduces the imine and not the starting ketones + aldehydes (carbonyls)

Question 29

why is using Me-I as a hydride donor badddd

Answer 29

bc u cant stop it after the first alkylation (adding an alkyl group to a molecule)

it keeps on adding Me until its quaternaryyyy.

arrow from amine N to Me and then to I,, kicks off I and Me stays. then repeats till all H’s are Me/R groups.

Question 30

Na BH4 is used to what

Answer 30

joins carbonyl aldehydes and amines,, gets rid of carbonyl group and in its place will be a NH and then the rest of the amine

Question 31

C - N explain partial charges

Answer 31

C is partially positive
N is partially negative

bc of electronegativity difference

Question 32

what does N act like

Answer 32

like a nucleophile bc it has a lone pair

Question 33

sources of e-

Answer 33

lone pair
- charge
bonds

Question 34

whn electrons are moved,, where does the arrow normally end

Answer 34

somewhere good
somewhere that can hold a
(-) well