Organic Chemistry Ch. 2

Question 1

____ is the most similar of all isomers

Answer 1

Conformational

Question 2

Ring strain arises from what 3 factors

Answer 2

Angle strain, torsional strain, nonbonded strain/Van der Waals repulsion

Question 3

Define angle strain

Answer 3

when bond angles deviate from ideal values by being stressed or compressed

Question 4

Define torsional strain

Answer 4

when cyclic molecules have to assume conformations of eclipsed or gauche interactions

Question 5

Define nonbonded strain (aka van der Waals repulsion)

Answer 5

when nonadjacent atoms or groups compete for same space

Question 6

List the 3 main conformations of cyclohexane

Answer 6

Chair, boat, twist/skew boat

Question 7

Define flagpole interactions

Answer 7

van der Waals strain between the two hydrogen atoms pointing inward, towards each. Contribute toward ring strain of boat conformation

Question 8

How does a chair flip impact the equatorial and axial positions? how does it impact the dashes and wedges

Answer 8

Equatorial positions become axial and axial positions become equatorial. It doesn’t impact dashes and wedges

Question 9

___ groups favor equatorial position

Answer 9

bulky

Question 10

Define chiral molecule

Answer 10

A molecule that lacks an internal plane of symmetry and whose mirror image cannot be superimposed

Question 11

Define achiral molecule

Answer 11

Mirror images that can be superimposed

Question 12

Enantiomers have identical physical and chemical properties, except with __ and __

Answer 12

Optical activity and and reactions in chiral environments

Question 13

What is an optically active compound

Answer 13

ability to rotate plane polarized light

Question 14

How does an enantiomer interact with optical activity?

Answer 14

they rotate plane-polarized light with the same magnitude in the opposite directions (different optical activity) and react differently in chiral environments

Question 15

Define d-/(+) enantiomers

Answer 15

rotate plane polarized light clockwise (to the right)

Question 16

Define l-/(-) enantiomers

Answer 16

rotate plane polarized light counterclockwise (to the left)

Question 17

Define racemic mixture

Answer 17

When d- and l- enantiomers are present in equal concentration; rotations cancel each other out, so no optical activity is observed

Question 18

Reacting 2 enantiomers with an enantiomer of another compound produces _____

Answer 18

2 diastereomers

Question 19

For any molecule with n chiral centers, there are ___ possibilities of stereoisomers

Answer 19

2^n

Question 20

Define relative configuration

Answer 20

configuration in relation to another chiral molecule

Question 21

Define absolute configuration

Answer 21

describes spatial arrangement of atoms or groups independent of other molecules

Question 22

Can double bonds have chiral centers?

Answer 22

No