2 Isomers

Question 1

conformational isomers

Answer 1

same molecule rotated differently around a bond

Question 2

Newman projection

Answer 2

sideways view of molecule along one bond

Question 3

anti-staggered

Answer 3

highest priority groups 180º apart

Question 4

eclipsed

Answer 4

steric hindrance

Question 5

gauche

Answer 5

in between anti-staggered and eclipsed

Question 6

cyclic conformers

Answer 6

introduce ring strain

most stable: cyclohexane chair conformation

Question 7

in ring conformers, one prefers the bulky groups to be in the _______(axial/equatorial) position

Answer 7

equatorial

in axial position, they introduce flagpole strain – can cause ring inversions

Question 8

configurational isomers

Answer 8

have to break bonds to move positions

Question 9

chiral carbons (stereocenters)

Answer 9

4 unique substituents

Question 10

enantiomers

Answer 10

nonsuperimposable mirror images (different compounds)

Question 11

diastereomers

Answer 11

> 1 stereocenter
nonsuperimposable non-mirror images

2^n configurations

Question 12

cis/trans isomers

Answer 12

differ in configuration across double-bond/ring

Question 13

meso compounds

Answer 13

> 1 chiral center & internal plane of symmetry

same substituents on different chiral centers

Question 14

(Z) and (E) forms

Answer 14

absolute configuration around double bond
> 2 substituents

“ze zame zide”: highest priority groups on the same side of double bond

Question 15

(R) and (S) forms

Answer 15

concerned with stereocenters

Question 16

Fischer projections

Answer 16

can be used to show absolute configurations