C5 Monozaharide 2 [PDF]

Zitiervorschau

 Monozaharide - Proprietati chimice  Reducere  H2 /cat, electrochimic, [H]

Emulgatori, vitamina C, umectanti, indulcitori, organogelifianti

Guma de mestecat

 Oxidare  oxidare blândă - cu apă de clor sau brom, oxid umed de argint Ag2O, reactiv Fehling, sau apă oxigenată – acizi aldonici CHO

COOH

H C OH

H C OH

HO C H H C OH

oxid.

H C OH CH2OH D-Glucoza

HO C H -H2O

H C OH H C OH

O H HO H H

CH2OH Acid D-Gluconic

C C OH O C H C C OH CH2OH -Lactona

 oxidare energică - cu acid azotic concentrat - acizi zaharici

CHO

COOH

H C OH HO C H H C OH H C OH CH2OH D-Glucoza

H C OH HNO3

HO C H H C OH H C OH COOH Acid zaharic

 oxidare enzimatica - acizi uronici

CHO

CHO

H C OH

H C OH HO C H H C OH

[O]

ox. C6

H C OH

COOH Acid D-glucuronic

D-Glucoza

HO C H H C OH H C OH COOH Acid zaharic

CHO

CO

H C OH -H2O

H C OH O HO C H H C H C OH COOH -Lactona

H C OH H C OH

CH2OH

COOH

HO C H

H C OH 2[H]

HO C H H C OH H C OH COOH Acid D-glucuronic

 Acţiunea acizilor şi bazelor asupra monozaharidelor

 Acizii minerali, la cald

CHOH

CHOH

CH2OH CHOH

HCl -3H2O

CHO

HOCH2

CHOH

CHOH

CHOH

CHOH

CHO O Furfurol

HCl -3H2O

HOCH2

O

CHO

CHO H3C CO CH2 CH2 COOH + HCOOH Acid levulic

 Epimerizarea - baze slabe ( lapte de var) Monozaharide epimere – difera prin configuratia primilor 2 atomi de carbon (glucoza, fructoza, manoza)

HO

C1H2OH

C1H-OH

C2 O

C2 O

HO C H

HO C H

C1H OH C2 O HO C H

C1H O C2 OH HO C H

D-Fructoza

C1HO C2 OH HO C H

C1HO HO C2 H2O + HO C H

C1HO C1HO H C2 OH HO C2 H HO C H + HO C H + HO D-Glucoza

D-Manoza

 Reacţiile monozaharidelor cu fenilhidrazina CHO

CH=N-NH-C6H5

H C OH HO C H

C6H5-NH-NH2

H C OH H C OH

- H2O

CH2OH D-Glucoza

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

H C OH H C OH CH2OH

C6H5-NH-NH2 (exces) - C6H5-NH2 - NH3

CH2OH Fenilhidrazona D-Glucozei

C O HO C H H C OH H C OH CH2OH

CH=N-NH-C6H5

CH=N-NH-C6H5 C O HO C H

CH=N-NH-C6H5

C6H5-NH-NH2 - H2O

C N NH-C6H5 HO C H H C OH H C OH CH2OH Osazona

Monozaharidele epimere dau aceeasi osazona !

C1HO

C1H=N-NH-C6H5

2 HO C H

HO C H

C6H5-NH-NH2

C1H=N-NH-C6H5 C2 O

2 HO C H C6H5-NH-NH2

- H2O

D-Manoza

HO C H

(exces)

HO C H

- C6H5-NH2 - NH3

Fenilhidrazona

C1H2OH

C1H2OH

C2 O

C1H N-NH-C6H5

C2 N-NH-C6H5 C6H5-NH-NH2

C2 N-NH-C6H5

HO C H

C6H5-NH-NH2 - H2O

(exces)

HO C H

D-Fructoza

- C6H5-NH2

HO C H Osazona

Fenilhidrazona

Aplicatie - transformarea unei aldoze in cetoza epimera C1H N-NH-C6H5

C1HO

C1H2OH

C2 N-NH-C6H5

C2

C2 O

HO C H Osazona

H2O

O

HO C H Osona

2 [H]

HO C H Cetoza

 Eterificarea grupelor hidroxil din monozaharide  Hidroxilul glicozidic - alcool metilic în prezenţă de acid clorhidric uscat  Grupe hidroxil poz. 2-6 - iodură de metil în prezenţă de oxid de argint, sau sulfat de metil şi hidroxid de sodiu

H C OH

H C OCH3

H C OH

H C OH

HO C H

O

CH3OH +

H

HO C H

O

H C OCH3 4CH3I Ag2O

H C OCH3 O H3CO C H

H C OH

H C OH

H C OCH3

H C

H C

H C

CH2OH

CH2OCH3

CH2OH

1,2,3,4,6-pentametil-D-Glucoza H C OH

H C OCH3 H C OCH3 O H3CO C H

H2O +

H

H C OCH3 O H3CO C H

H C OCH3

H C OCH3

H C

H C

CH2OCH3

CH2OCH3

2,3,4,6-D-tetrametilglucoza

 Utilizare - stabilirea naturii piranozice sau furanozice a ciclurilor H C OCH3 H C OCH3 O H3CO C H

H2O

H C OH

CHO

H C OCH3 O H3CO C H

H C OCH3 H3CO C H

H C OCH3

H C OCH3

H C OCH3

H C

H C

H C OH CH2OCH3

CH2OCH3

CH2OCH3

[O]

Ciclu piranozic

COOH H C OCH3 H3CO C H H C OCH3 H C OH CH2OCH3

COOH

CO

-H2O

H H3CO H H

C OCH3 O C H C OCH3 C CH2OCH3

lactona

H C OCH3 ox.

H3OC C H H C OCH3 COOH Acid trimetoxiglutaric (xiloglutaric)

 Cetalizarea grupelor hidroxil - Reactie de protejare H C O

H C OH H 3C

H C OH HO C H

O

C

CH3 C

H C O

O

H3 C

H 3C

C H 3C

HO C H

CH3 O

O C H O C H H C

H C

CH2OH 1,2,3,4-Diizopropilidengalactopiranoza

CH2OH Galactopiranoza

CH2OH OH O

H3C H3C

OH OH OH

C O

H3C H3C

O C

CH2OH O O O O C

CH3 CH3

CH2OH

CHO H C HO C

 Exemplusinteza Vitaminei C

OH

H C

H

H2/Ni

HO C

OH

H C

H

OH

H C

OH

H C

OH

H C

OH

Acetobacter xylinum

O

C

HO

C H

H

CH3COCH 3

C OH

O

H

C H CH2OH

C

KMnO 4/HO

-

O

O

HO C

C H

HO C

C

O

C OH

CH2 O 2,3:4,6-di-O-isopropiliden-a-L-sorbofuranoza O C COOH

O C

C

HO

C H

C H

COOH

H

H

O

O C H

H2SO4

CH2OH a-L-sorbofuranoza

O

OH

O

O C

C H

O C H

H C

HO

CH2OH L-sorboza CH2OH

CH2OH HO

C

H

C

CH2OH sorbitol

CH2OH

OH

C

HO

[O]

H C

CH2OH D-glucoza

CH2OH

MeONa/MeOH HCl

C H CH2 O acid 2,3:4,6-di-O-isopropiliden-2-ceto-L-gulonic

HO H HO

C OH C H

CH2OH acid 2-ceto-L-gulonic

O

H C HO

C H

CH2OH acid -L-ascorbic

 Esterificarea grupelor hidroxil din monozaharide  Acetilare - reactie stereoselectiva

CH2OH

CH2OAc

O OH OH OH a-D-Glucoza

OH

O

Ac2O Py

OAc

OAc OAc OAc -D-Glucoza-pentaacetat

ZnCl2 ,0o C

 Aplicatii - sinteze de glicozide fenolice

SN2 inversie

SN2 inversie

 Reacţii de interconversie ale monozaharidelor  Reacţii de scurtare de catenă (reacţii de degradare) CHO H HO H H

CN

CH=N-OH

C OH C H H2N-OH - H2O C OH C OH CH2OH

H HO H H

D-Glucoza

C OH Ac2O C H - H2O C OH C OH CH2OH Oxima

C OH C H C OH C OH CH2OH

D-Glucoza

C OAc C H 2) - HCN C OAc C OAc CH2OAc

CHO HO C H H C OH H C OH CH2OH

Wohl

D-Arabinoza

COOH

CHO H HO H H

H AcO H H

1)+ 5 CH3OH / CH3O-Na+ - 5 CH3COOCH3

ox.

H HO H H

C OH C H C OH C OH CH2OH

CHO H2O2 Fe(OAc)3

Acid D-gluconic

Sare de calciu

HO C H H C OH H C OH CH2OH D-Arabinoza

Ruff

 Reacţii de lungire de catenă CN HC O HO C H H C OH H C OH CH2OH

HCN

H HO H H

CN

C OH C H C OH C OH CH2OH

+

HO HO H H

C H +H2O C H C OH C OH CH2OH

D-Arabinoza

COOH H + H2O HO H H

COOH

C OH HO C H C H + HO C H H C OH -H2O C OH H C OH C OH CH2OH CH2OH

H HO H H

CO

CO

HO C OH C H O + HO H C H C OH CH2OH

C H C H O C C OH CH2OH

-Lactone

Acizi aldonici

CHO

CHO Na(Hg)

H C OH HO C H

+

HO C H HO C H

Kiliani-Fischer D-Glucoza

D-Manoza

 Transformări biochimice ale hidraţilor de carbon  Fermentatia alcoolica

C6H12O6

- procese anaerobe - procese aerobe

2 C2H5OH + 2 CO2