Are D-fructose and L-fructose anomers, epimers, diastereomers, enantiomers, or not stereoisomers?

1 Answer
Feb 4, 2016

If you are talking about the straight chain forms, they are stereoisomers that are enantiomers.

Explanation:

The Fischer projections of D- and L-fructose are:

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Are they anomers?

No, because anomers occur only in cyclic structures.

Are they epimers?

No, because epimers differ at only one chiral centre. D- and L-fructose differ at #"C3"#, #"C4"#, and #"C5"#.

Are they enantiomers?

Yes, because every chiral carbon in one isomer has the opposite configuration in the other isomer. They are nonsuperimposable mirror images of each other.

Are they diastereomers?

No, because diastereomers are stereoisomers that are not enantiomers.

Are they stereoisomers?

Yes, because they are isomers that differ only in the spatial arrangements of their atoms.