Exam 5: Stereochemistry

One of the stereoisomers of the following oblongolide structure is a natural product isolated from a fungus and has been found to contain antiviral and cytotoxic activities (J. Nat. Prod. 2010, 55). How many stereoisomers exist for this structure?

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

Does this molecule have a mirror plane? If so, represent where the plane would be with a dashed line.

Which of the following incorrectly describes cis-1,2-dimethylcyclopentane?

How many asymmetric carbon atoms are present in the following compound?

Calculate the e.e. of a mixture containing 8.0 g of (-)-glyceraldehyde and 2.0 g of (+)-glyceraldehyde.

Star the asymmetric carbons in the structure below.

Would a 50:50 mixture of (2R,3R)-2,3-dibromobutane and (2R,3S)-2,3-dibromobutane be optically active? Explain.

Is the molecule shown below chiral or achiral? CH₃CH₂CH(CH₃)CH₂CH₃

Draw the Fischer projection of (2R,4R)-2,4-dibromopentane.

Provide a Fischer projection of (2S,3S,4S)-2,3,4-trichloroheptane.

Compounds that rotate the plane of polarized light clockwise are called ________.