Exam 2

Question 1

Methane

Answer 1

one carbon

Question 2

Ethane

Answer 2

Two Carbons

Question 3

Propane

Answer 3

Three Carbons

Question 4

Butane

Answer 4

Four Carbons

Question 5

Pentane

Answer 5

Five Carbons

Question 6

Hexane

Answer 6

Six Carbons

Question 7

Heptane

Answer 7

Seven Carbons

Question 8

Octane

Answer 8

Eight Carbons

Question 9

Nonane

Answer 9

Nine Carbons

Question 10

Decane

Answer 10

Ten Carbons

Question 11

Undecane

Answer 11

Eleven Carbons

Question 12

Dodecane

Answer 12

Twelve Carbons

Question 13

Stereochemistry

Answer 13

noted whether substituents are cis or trans

Question 14

Newman Projection

Answer 14

orientation of atoms when looking down a specific C-C bond

Question 15

Staggered projection

Answer 15

Most Stable and less energy

Question 16

Eclipsed Projection

Answer 16

least stable and more energy

Question 17

Conformational Analysis

Answer 17

determine energy given off of atoms being oriented next to one another
- H/H eclipsed= 1 kCal/mol
- CH3/H eclipsed = 1.3 kCal/mol
- CH3/CH3 Gauche = 0.9 kCal/mol

Question 18

Lowest energy conformer

Answer 18

trans orientation

Question 19

Torsional Strain

Answer 19

all eclipsing interactions

Question 20

Cyclohexane

Answer 20

six member ring - Chair, no torsional or angle strain, Axial and equatorial bonds (3 up and 3 down)

Question 21

Chair Flip

Answer 21

Axial and Equatorial bond switch, Front carbons stay in the front

Question 22

Substituted cyclohexane

Answer 22

favored in the equatorial position

Question 23

Bycyclic Alkanes

Answer 23

two rings share one or more carbons
- Spiro = 1 shared carbon
- Bicyclo = 2+ shared carbons

Spiro/Bicyclo [# of carbons to complete one side of the ring - # of carbons to complete the other side of the ring - # od carbons in the bridge] # of total Carbons

Question 24

Molecular Chirality

Answer 24

Chirol - molecule can’t be placed upon its mirror image
Non-chirol - molecule can be placed upon its mirror image

Question 25

Chirol

Answer 25

sp3 atom with 4 different substituted groups

Question 26

Enantiomers

Answer 26

the R or S of the chirol center switches to the other

Question 27

Determining R or S

Answer 27

1. Rank groups 1-4 (H is always 4, atomic number - largest to smallest)
2. orient so 4 priority is in the back plane
3. Read groups 1-3 from highest to lowest - clockwise = R, Counter clockwise = S

Question 28

Diastereoisomers

Answer 28

One chirol center in common, one different

Question 29

Meso Compounds

Answer 29

• inner mirror plane
• 2 or more chirol center
• achirol, rotations cancel out

Question 30

Naming with stereochemistry

Answer 30

R and S are added when there are wedges or dashes

Question 31

Racemic

Answer 31

50/50 mixture of enantiomers

Question 32

Fisher Projections

Answer 32

2-D representation of 3-D chirol centers
- horizontal lines = in the plane towards me
- vertical lines = in the flane away from me