Answer to Question #191457 in Inorganic Chemistry for Kwabena Addo

Question

Briefly distinguish between the following terms with appropriate examples: 

a. Epimers and diastereomers

b. Aldoses and ketoses

c. Alpha (α) anomer and beta (β) anomer

d. D glucose and L glucose

e. Pyranose and furanose

Answer 1

Diastereomers are compounds that contain two or more chiral centres and are not mirror images of each other. ... Epimers are diastereomers that contain more than one chiral center but differ from each other in the absolute configuration at only one chiral center.

Ketose and aldose are monosaccharides which can be differentiated based on the group they contain. An aldose is defined as a monosaccharide whose carbon skeleton has an aldehyde group. ... Ketose is a monosaccharide whose carbon skeleton has a ketone group

α (Alpha) – the name given to the configuration of a cyclic sugar where the oxygen on the anomeric carbon is on the opposite face of the ring relative to the substituent on the other carbon flanking the ring oxygen. Contrasted with beta (β) which is where the two substituents are on the same faces of the ring.

l-Glucose is an organic compound with formula C₆H₁₂O₆ or O=CH[CH]₅H, specifically one of the aldohexose monosaccharides. As the l-isomer of glucose, it is the enantiomer of the more common d-glucose. l-Glucose does not occur naturally in higher living organisms, but can be synthesized in the laboratory.

The key difference between furanose and pyranose is that furanose compounds have a chemical structure that includes a five-membered ring system containing four carbon atoms and one oxygen atom whereas pyranose compounds have a chemical structure that includes a six-membered ring structure consisting of five carbon