1.cyclic structure of D-glucose 2.Mutarotation 3.Hemeacetal 4.Acetal form of glucose 5.Ring size determination

2. Presented by :-
1.S. Moshiur Rahman
2.Asraful Islam Rayhan
3.Trina Mitra
4.Amit Kumar
5.Shaharul Islam
6.Shorrowar Azom
Dept. of Pharmacy
JESSORE UNIVERSITY OF SCIENCE & TECHNOLOGY

3. 1.cyclic structure of D-glucose
2.Mutarotation
3.Hemeacetal
4.Acetal form of glucose
5.Ring size determination

5. Carbohydrates are the organic molecules that are
composed of elements carbon , hydrogen and oxygen.
Carbohydrates have the general formula Cx(H2O)y .
Examples:- Glucose , Fructose etc.

8. Glucose
( An aldohexose )

10.  Glucose is colorless & odorless.
White crystalline solid.
 Melting point 146℃.
 Glucose is :-
- Soluble in water.
- Sparingly soluble in alcohols.
- Insoluble in ether.
Aqueous solution of glucose is dextrorotatory.

11.  Action as a Reducing Agent :-

12.  Reaction with Hydrogen Cyanide :-

20. O
H
HO
H
HO
H
H
OHH
OH
OH
O
H
HO
H
HO
H
OH
OHH
H
OH
hemiacetal
4H-Pyran
O
D-glucopyranoses
alpha beta

21. OH
H
H
H OH
HO H
O
H
HOHO
H
OH
H
H OH
HO H
O
H
HOHO
O
furan
alpha furanose form beta furanose form
D-glucofuranoses

26. Mutarotation

27. Mutarotationis the change in the optical
rotation because of the change in the
equilibrium between two anomers ,
when the corresponding stereocenters
interconvert.

30. anomer anomer
The specific rotation of pure a-D-glucose or b-D-glucose
changes over time to reach an equilibrium (mutarotation)

32. We can methylate the various OH groups,
converting them into OMe. Two kinds of OH
•OH at anomeric carbon
•OH on backbone
One of the backbone OH groups may be bonded to
the anomeric carbon to form a ring. We seek to
detect which one.
First review characteristics of hemiacetals
and acetals.

33. Ring sizes (furanose or pyranose) have been determined using
alkylation as a key step.
CH2OCH3
H OH
OCH3H
HCH3O
H OCH3
CH O
This carbon has OH
instead of OCH3.
Therefore,its O was the
oxygen in the ring.

34. Ring flips can occur. Generally the conformation
with large groups equatorial dominate.
Generally the CH2OH should be made equatorial

35. • The size of the ring can be determined from the structure
of the open-chain form.