Lecture 29

To which classes of sugars do the following monosaccharides belong? Which is D and which is L?

 

Lecture 30

1. After a series of Kiliani-Fischer syntheses on (+)-glyceraldehyde, an unknown sugar is isolated from the reaction mixture. The following experimental information is obtained:

1. (1) Molecular formula C₆H₁₂O₆ .

(2) Undergoes mutarotation.

(3) Reacts with bromine water to give an aldonic acid.

(4) Reacts with phenylhydrazine to give an osazone, mp 178°C.

(5) Reacts with HNO₃ to give an optically active aldaric acid.

(6) Ruff degradation followed by HNO₃ oxidation gives an optically inactive aldaric acid.

(7) Two Ruff degradations followed by HNO 3 oxidation give meso -tartaric acid.

(8) Formation of the methyl glycoside (using CH₃ OH and HCI), followed by periodic acid oxidation, gives a mixture of products that includes (+)-glyceraldehyde.

(a) Draw a Fischer projection for the open-chain form of this unknown sugar.

 

Lecture 32

1.  Phenyl acetaldehyde

2.  Glutamate would travel down on the column rapidly compared to lysine. This is because in glutamate the negatively charged side chain would be repelled by the negatively charged sulfonic acid groups of the resin. On the other hand, in case of lysine, the positively charged side chain would intract with negatively charged sulfonic acid.

3.

 

Lecture 33

1.  20³ 3. 41%

Lecture 38