HYDROXY (OXY) ACIDSISOMERISM, NOMENCLATURA

1. Chain СН3

СН3 СН2 СН СООН СН3 С СООН ОН ОН2-hydroxybutanoic acid 2-hydroxy- 2-

methylpropanoic acid ОН-group positionСН3 СН СН2 СООН СН2 СН2 СН2 СООН ОН ОН3-hydroxybutanoic acid 4-hydroxybutanoic acid

Hydroxy acids.

СOOH СOOH СOOH CHOH CH2 CHOH CH2

CH3 CHOH CHOH C OH

Lactic acid COOH COOH COOH Malic acid Tartaric acid CH2

COOH

Citric acid

Salicylic acid

CОOH

COOH

OH

[α]D = L*100c*l

Optical Isomerism 1.Enantiomerism (Mirror Isomerism)

2.Diastereomerism

R

R''' C* R' Assymetrical Carbon (C* -SP3- hybrid)

R''

Lactic acid: Enantiomers

COOH HOOC Glyceric aldehyde

H C* OH HO C* H C O C O

CH3 CH3 H H

D(-) – Lactic acid (+)L – Lactic acid H C* OH НО C* H

CH2OH CH2OH

D(+) L(-)

Chiral objects

Chiral moleculars

X=2n, n-number of assymetrical carbons (chiral) X- number of stereoisomers

COOH COOH COOH COOH

H C* OH НО C* H H C* OH HO C H

HO C* H H C* OH H C* OH HO C H

COOH COOH COOH COOH

Clockwise Counter clockwise

D(+) – Tartaric L(-) –Tartaric Mesotartaric

acid acid acid

Enantiomers Diastereomers

(Grape acid - Racemic mixer)

Tartaric Acid

1. R CH COOH H+ + R CH COO-

OH OH2. R CH COOH + NaOH R CH COONa OH OH

3. R CH COOH + R'OH R CH COOR' + H2O OH OH Ether4. Haloanhydrates, amides.

R CH C R CH C OH OH

-Н2О

OCl

O

NH2

Chemical Properties

5. R СН С ОН

6. R CH C OH

О

ОН+ 2Na R CH C

ONa

O

ONa+ H2

O

OH+ [O] R C C

O

OOH

Oxoacid

t0, Н+

-H2O

1. Decomposition of α-hydroxy acids

R' O

R CH COOH R C + H COOH

OH H Formic acid

(R')

2.

R CH OH HO C O

+ CH R R HC C O

C HO O C CH R

α-hydroxy acid ОН O Lactid

t0

α

О

Speсial Properties.

О

b)

R CH CH2 COOH R CH CH COOH

ОН unsaturated acid

β-hydroxy acid c) CH2 CH2 H2C CH2

R CH C O R CH C O

OH HO O

γ-lactone

Oxidation O

HO - CH2 - (CH2)n - COOH → C - (CH2)n COOH

H ↓ [O]

HOOC - (CH2)n - COOH

[O]

CH3 -CH- COOH → CH3 – C- COOH → CH3 - C O

OH O -CO2 H

t0

-H2O

β

γ

-H2O

COOH

COOH

CH-O

CH-OHCOOH

COOH

HO-CH

O-CHCu

HO

OHH

H

COOH

COOH

CH-O

CH-O

H

COOH

COOH

O-CH

O-CHH

Cu:

:

+

+

Test on Tartaric Acid

-2Н2О

Phenoloacids. COOH COOH COOH

OH

OHOH

+ FeCl3 Violet colour

о-Oxybensoic acid м- Oxybensoic acid p-Oxybensoic acid

(Salicilic)

O Na

+ CO21250, 5 атм.

OH

C

O Na

+HCl-NaCl

OH

COOH

pKa=2,98OH

O

COH

О

O C

O

CH3

C O

OH

CH3CO

OH

OH

COOH

Acetylsalicilic acid (aspirin)

+Na2CO3

-CO2, -H2O

OH

OH

OH

C

C

C

O

O

O

O Na

O CH3

O C6H5

Methylsalicilate

Phenylsalicilate

(salol)

+СH3OH (H+)-H2O

-H2O

C6H5OH

СООН

ОН

ОННО

tº

ОНОННО

Gallic acid Pyrogallol

COOH COOH

OH

OHHOOHNH2

P-Aminosalicilic acid Gallic acid

С6H5 CH COOH

OH

Mindalic acid

Oxoacids (Ketoacids).Trivial name IUPAC name Structure

Glioxalic Oxoethanoic

Н С СOOH O

Pruvic 2-OxopropanoicH3C C COOH

O

Acetoacetic 3-OxobutanoicH3C C CH2 COOH O

Oxaloacetic 2-Oxobutanedioic HOOC C CH2 COOH O

α-Ketoglutaric 2-Oxopentanedioic HOOC- C CH2 - CH2

COOH

o

Oxoacids (Ketoacids) Kеtо-Enol

Tautomerism СH3

C O

H C H

C O

O C2H5

δ+

δ+

δ-

δ-

CH3

C OH

CH

C O O C2H5

Acetoacetic ether

Кеtо-form

93%

Еnol-form

7%