Isomerism

Question 1

Determine if these are:

constitutional isomers

conformational isomers

enantiomers

diastereomers

or the same molecule

Answer 1

enantiomers

Question 2

If your molecule is R R and the isomer is R S

are these diastereomers or an enantiomers?

Answer 2

diastereomers

Question 3

meso compound

Answer 3

molecules that are achiral and contain tetraheral stereocenters

Question 4

Determine if these are:

constitutional isomers

conformational isomers

enantiomers

diastereomers

or the same molecule

Answer 4

conformational isomers

Question 5

Determine if these are:

constitutional isomers

conformational isomers

enantiomers

diastereomers

or the same molecule

Answer 5

diastereomers

Question 6

How many stereocenters are in this structure?

Answer 6

8 stereocenters

Question 7

conformational isomers

Answer 7

compounds that have the same molecular formula but differ due to rotations about single bonds

(i.e. Newman projection rotations)

Question 8

enantiomers

Answer 8

a chiral molecule’s non-superimposable mirrored structure

Question 9

How would you classify cis/trans isomers?

Answer 9

Diastereomers

Question 10

formula for max number of configurational isomers possible?

Answer 10

2ⁿ (where n is the number of stereocenters)

Question 11

Determine if these are:

constitutional isomers

conformational isomers

enantiomers

diastereomers

or the same molecule

Answer 11

diastereomers

Question 12

diastereomers

Answer 12

configurational isomers that are NOT mirror images

Question 13

Will a chair with a larger substituent in the axial position be the preferred conformation over the larger substituent in the equatorial position?

Answer 13

No. The larger substituent in equatorial position is the preferred conformation

Question 14

stereoisomers

Answer 14

compounds that have the same molecular formula, and same connectivity, but differ in some other way

Question 15

What type of isomer does a chair flip result in?

Answer 15

conformational isomer

Question 16

If your molecule is R R and the isomer is S S

are these diastereomers or an enantiomers?

Answer 16

enantiomers

Question 17

constitutional isomers

Answer 17

compounds that have the same molecular formula but different connectivity

Question 18

Determine if these are:

constitutional isomers

conformational isomers

enantiomers

diastereomers

or the same molecule

Answer 18

diastereomers

Question 19

Organize the following from highest to lowest ring strain:

cycloheptane

cyclopropane

cyclohexane

cyclopentane

cyclobutane

Answer 19

highest ring strain

cyclopropane

cyclobutane

cycloheptane

cyclopentane

cyclohexane

lowest ring strain

Question 20

Determine if these are:

constitutional isomers

conformational isomers

enantiomers

diastereomers

or the same molecule

Answer 20

enantiomers

Question 21

configurational isomers

Answer 21

compounds that have the same molecular formula and same connectivity but differ in a way other than bond rotation

Question 22

Which of the following has relatively identical physical and chemical properties?

constitutional isomers

diastereomers

enantiomers in a chiral environment

enantiomers in an achiral environment

Answer 22

enantiomers in an achiral environment have relatively identical chemical and physical properties

Question 23

Put the following alkene isomers in order from most stable to least stable:

cis disubstituted

tetrasubstituted

trans disubstituted

monosubstituted

disubstituted

trisubstituted

Answer 23

Most Stable

tetrasubstituted

trisubstituted

disubstituted

trans disubstituted

cis disubstituted

monosubstituted

Least Stable