Practice quiz 3 Newman projections and fischer projections PDF

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Summary

This is Professor Mohlers organic chemistry 241 practice quiz for quiz 3. On this quiz there is newman projections, chiral centers, and fischer projections...

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Name_______________________ page 1 1. Rotating the back carbon by 60o, draw the six conformations about the C2-C3 bond of the compound to the right, putting C2 in front. Rank these projections in order from 2 4 lowest energy (=1) to highest energy. If two conformations are the same energy, give 1 3 them the same number.

2. Draw bond-line structures for two diastereomers of the compound on the right. In column 2, draw a chair conformation of each diastereomer, and then show the results from flipping this chair in column 3. Put a J in the box with the most stable of all 4 chairs. diastereomer 1 (bond-line): diastereomer 1 (chair):

flipped chair of 1:

Br

diastereomer 2 (bond line): diastereomer 2 (chair): Br

3. Consider the following reaction.

flipped chair of 2:

Br

OH

HBr SN1

A

+

B

Br

page 2 (note: this question was written for use after chapter 7, when students would know this reaction, in which the OH is replaced by a Br atom, as a wedge in one structure and a dash in the other.)

a. In the appropriate box, give bond-line structures of steroisomers A and B and draw the Fischer projections of each. Fischer projection of A

Bond-line structure of A

Fischer projection of B

Bond-line structure of B

b. Draw the Fischer projections of any additional stereoisomers of A and B, and label them C, D, etc., as needed. Do not draw any duplicate molecules and do not duplicate A and B.

b. Next to the structures above, indicate whether each is chiral or achiral. c. Fill in the blanks below. Compound ________ and compound _________ are enantiomers. Compound ________ and compound _________ are diastereomers. Are any of these stereoisomers a meso compound?

If so, which?...