Exam 4: Isomers: the Arrangement of Atoms in Space

The specific rotation of a pure substance is -5.90°.What is the percentage of this isomer in a mixture with an observed specific rotation of -2.95°?

Provide a perspective drawing of (2R,3S)-1,2,3-trichloropentane.

Identify the compound(s)with asymmetric centers.

The compound below contains an asymmetric center at nitrogen.Why can't individual stereoisomers of this compound be isolated at room temperature?

Label each asymmetric center in the compound below as R or S.

Which of the following compounds has an S configuration?

Structure of cholesterol is shown below.How many stereoisomers exist for this molecule?

A sample of (+)and (-)-3-chlorohexane has a rotation of -20 degrees.Pure (+)-3-chlorohexane has a rotation of +40 degrees.Calculate the enantiomeric excess and the amount of (-)and (+)-3-chlorohexane in the original sample.

Which of the following is chiral?

In the Fischer projection below,what are the configurations of the two asymmetric centers?

Which of the following statements correctly pertains to a pair of enantiomers?

Draw any diastereomer of (2R,3R)-2,3-dichloropentane.Be careful to indicate proper stereochemistry.

Is the molecule shown below chiral or achiral?

Is the molecule shown below chiral or achiral?

Provide a careful structure for (2S,3S)-2,3-dibromohexane.

Which of the following is a true statement?

Which of the following terms best describes the pair of compounds shown: enantiomers,diastereomers,or the same compound?

Provide a perspective drawing of the enantiomer of (2R,3S)-1,2,3-trichloropentane.

What is the relationship between the structures shown below?

Which of the following terms best describes the pair of compounds shown: enantiomers,diastereomers,or the same compound?