7. Structural Isomerism.
Oxo-group position (only for ketones)
Carbon Chain Isomerism
7
CH2 C
O
CH2 CH3CH3CH3
C
O
CH2
CH2
CH3
Pentanone-2 Pentanon-3
CH3 C
O
CH2 CH2 CH3
CH3
C
O
CH CH3
CH3
Pentanone-2 3-methylbutanone
10. С О
δ+ δ-
Chemical Properties.
Addition to carbon - hetero double bonds (AN)
These bond is polar (have a large difference in electronegativity between
the two atoms) consequently carbon carries a partial positive charge. This
makes this atom the primary target for the nucleophile.
11. Nucleophilic Addition (AN)
δ+ δ-
Aldehyde or
ketone
slow
Nu─
Intermediate
product
fast
Product
Nu– C –OC = O Nu– C –OH
: ‒ H+
As Nu-agents can be: CN−
, H2O:, R−OH, :NH3
(:NH2R, :NHR2, :NR3) etc.
12. Decreasing of AN reactivity :
H–C > CH3–C > CH3–C– CH3 >
O
O
H
O
H
CH3–C– C6H5 > C6H5–C– C6H5
O O
13. Formalin solution
O
OH
OH
H– C –HH– C –H + HOH
..
δ+
OH
OH
ChloralhydrateChloral
δ-
O
H
C + H2
O CI3
C –C –HCI3
C
1. Addition of Water(hydration)
14. 2. Alcohols addition
Aldehyde Alcohol Hemyacetal Acetal
δ+
δ-
R′
OH
R– C –H R– C –HR –OH′
OR′
OR′
OR′
OH
R –C +
O
H
..
16. 3. Addition of sodium hydrosulphite:
δ-
O
OH
R–C +
O
CH3
δ+
:S –O – Na+
OH
OCH3
R– C – S–O– Na+
O
17. 4. Addition of HCN
17
+ C O
CH3
CH3
C
CH3
CH3
O HNCHCN
NaOH
Cyanohydrin
C O
CH3
CH3
N C: N C C
CH3
CH3
O
H
+
N C C
CH3
CH3
OH
Cyanid-ion Acetone Acetone
Cyanhydrin
18. ─ C – N–X
X = H, R, OH, NH2 etc.
δ+ δ- ‒H2O
Н
Н OH H
С = О + :N–X
Shiff’s Base
(if X = R,H)
– C = N – X
H+
··δ+ δ-
С = N–X + H2OС = O + H2N–X
5.
22. 22
OH CH2
O CH2
O CH2
O CH2
O CH2
OHn
a) Paraform- is the product of formaldehyde polymerisation
7. Aldehydes Polymerisation
CH
H
O
CH
H
O
CH
H
O
CH
H
O
CH
H
O
CH
H
O
C
H
H C C
OH OH
C
H
C
OH
C
O
H
OHOH
H H H
Ba(OH)2
b) Butlerov’s reaction (1861y) - first example of carbohydrate
obtaining.
23. 8. Red-Ox Reactions
a) Silver Mirrow Reaction (Tollen’s reaction)
23
CH3
C
O
H
CH3
C
O
OH
Ag(NH3
)2
OH
-Ag
Ethanal Ethanoic acid
25. СH3-CH2-C-CH3 2CH3COOH
25
Vargner's rule
Oxidation of asymmetric ketones go in a such a way that
oxo-group decomposed with the smallest radical
=
O
[O]
c) Ketone’s oxidation goes under harder than
aldehydes conditions with the chemical bond break.
27. e) The Cannizzaro reaction, named after its discoverer
Stanislao Cannizzaro, is a chemical reaction that involves the base-
induced disproportionation of an aldehyde lacking a
hydrogen atom in the alpha position. Cannizzaro first
accomplished this transformation in 1853, when he obtained
benzyl alcohol and benzoic acid from the treatment of
benzaldehyde with a base.
27
C
OH
+
C
OH
+ NaOH
CH
H
OH
+
C
O O Na
+
+1 +1
-1 +3
Benzaldehyde Benzyl Benzoic
Alkohol Acid Salt
28. 9. Carbonyl Compounds EN-OLisation
28
C
O
C
H
C
OH
C
Keto-form En-Ol-form
Iodoform Reaction
R C
O
CH3
I2, OH-
R C
O
O + CHI3
Acidic anion Iodoform