Summary AQA A level chemistry carbonyls revision notes

Carbonyl
ALDEHYDES Compounds
26.1 AND IKETONES

Aldehyde
-R CHO H OAldehyde turdiural
group
L benzene orbaldehyde
Ketone
- RCOR
H--QH Ketonc tuncthonol
group
propaaone

Primacy alcohols can be oxId1sed to aldehyces
Seeonday alcohols can be oxidised to ketones
acd1t1ed potassium dchronsade
lestng tor aldehydes and lketongs i
feblng's solutin.
- Aldehyde - blue solutin torms a bide red
- ketone - no VIsible prepitate
hange
Toleds reagent
Aldehyde - s1lver mirroc toans
- Ketone n0 visible

Physical Properties ot cacbonyl compounds
carbonyl yroup is pola,
-




dipola -dpala torces
solubility n water deureases as chan length ceases
Rlduction ot aldehydes and ketoaes
(arbonys can be educed to caleohols u[ing NabH4 Creleasea H:)
- Condtions wam, water solveat
Nudeophilie addition (eaction
-




H 1ons in the vmechansy cissociate from water salvent
H H H
’H -C-OH




equation tor redctin of propcnont to propn ?el
CH, Co CH 2CH’ cH, CH OH CH
Complete reduction ot bul2-enal
H -C--C-0 -H
H-(-ic-2Hz Cvergthng

, 26. 2 REACTIONS OF ALDEHYDES AND KETONES

The addit1cn ot HN to an aldehuda or ketone s usel as the
One crbon.
hydoxy n e product has ts alkyl chan extended by
G the -Ol and -CN qroups can also be conveetea
-



Keaaent - auditied KCN
HCN s a toxic o as, KCN is toXIC but sol1d
- Cond1t1ons - retlux n aldc soluton
Nucleophile uanide ICn?CEN
Ethanal +
CNZH:
Nitrie acbon
H IS number
Hc-H h the
chan

2-bydroxypcopanenitla
CH CHOHCN
Optical lnact1atyi
The reactin produces a racemc axtue because (3 s
plan, S0 there ss cn equal chane ot the nucleoph1le
alacking the cot trom above or
below the plane
Ihe ceaction ot aa symetical ketone torms an optca
nactivt procuct as uw ell, beLause theres na chirc carbo
Pentan-3one
H
’H,H,C -C-CN
HH,C cH, CH,