Exam 4: Isomers: the Arrangement of Atoms in Space

Can one predict whether a compound with a single asymmetric center is dextro- or levorotatory based on the R/S assignment at this asymmetric center? Explain briefly.

Consider the molecules with molecular formula C₂H₂Br₂Cl₂. a) Draw a structure that is optically inactive because it does not have an asymmetric center. b) Draw a structure that is optically inactive because it is a meso compound. c) Draw a structure that is optically active because it is chiral.

How many stereoisomers exist with the following basic connectivity? CH₃CHClCH₂CHClCH₃

Which of the following is/are optically inactive?

Provide a careful structure for (2R,3S,4S)-2-bromo-4-methyl-3-hexanol.

Identify all pairs of enantiomers.

What is the relationship between the following compounds?

Draw the structure of a meso form of 1,3-dichlorocyclopentane. Take particular care to indicate three-dimensional stereochemistry detail properly.

A solution containing 0.96 g of 2-bromooctane in 10 mL ether solution gave an observed rotation of -1.8° in a 10 cm cell at Calculate the specific rotation of this solution.

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

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

What is the configuration of the following compound?

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

The compound CH₃CHClCH₂CH=CHCH₂CH₃ contains only one asymmetric center. Explain why it has four stereoisomers.

Label the molecule shown as chiral or achiral.

Identify all identical compounds.

Which of the following compounds has an R configuration?

Identify the compounds that are not chiral.

(-)-Mandelic acid has a specific rotation of -158°. What would be the specific rotation of a solution which contains 40% (-)-mandelic acid and 60% (+)-mandelic acid?

Which of the following compounds is chiral?