class2 Flashcards
What are the optical isomers referred to as D and L?
They are independent of the D and L configuration in Fischer representation.
What is a racemic mixture?
An equimolar mixture of two optical isomers that is optically inactive.
How is the optical rotation of a mixture calculated?
It is the sum of the specific rotations of its constituents.
What is the specific rotation of D-glucose?
52.2°.ml/g.dm.
What is the result of synthesizing higher sugars from triose?
It is possible to obtain C4, C5, and C6 sugars through Kiliani-Fischer synthesis.
Which series do all sugars derived from D-glyceraldehyde belong to?
The D series.
What occurs during mutarotation?
The specific rotation of a-D-glucose and B-D-glucose stabilizes to an identical value.
What is the equilibrium composition after mutarotation of anomers?
64% B-anomer, 36% a-anomer, and 0.02% linear form.
What is the mechanism of cyclization for aldoses?
C1-C5 forms pyran, C1-C4 forms furan.
What is the mechanism of cyclization for ketoses?
C2-C5 forms furan, C1-C6 forms pyran.
In the cyclization of sugars, how do hydroxyl groups (OH) change position?
OH to the right goes below, OH to the left goes above.
Fill in the blank: A mixture of a-D-glucose and B-D-glucose is an example of _______.
anomeric solutions.
True or False: All natural sugars are part of the D series.
True.
