test 2 extra stereochem practice - page not foundweb.mnstate.edu/jasperse/chem350/test 2 extra...
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1
Organic Chemistry I Test 2 Extra Stereochemistry Practice Problems Page 1: Designate R/S Page 2: Chiral or Achiral? Page 3: Same, Enantiomer, or Diastereomer? A. Designate the R/S configuration for any chiral centers in the following molecules.
1.
2. 3.
4. 5.
6.
7.
8. 9.
10.
11. 12.
13.
14.
15.
16.
17.
18.
19.
20. 21.
22.
23. 24.
25.
26.
27.
28. 29. 30.
BrH HBr HH2N
BrHHO
H OH OHHHO
OHH
HO O NH2
H OHO H OH
OHBrH
HOO O
CH3H
O O
CH3H
NH
O
CH3HNH2
OHHHO OH
OHH
O
OHH
O HH3CO
CH3H
OHHO
NH2
H CH3 OHHH2N
OHH
CH3Br
CH3 CH3H HHO
O
H
NH2H
H
NH2H3C HCH3 CH3H HO
CH3 CH3H H
CH3HO
HCH3H H OH
O
H HClHO O
CH2OHHH
HOHO
H HHOHOH
OH3C
H
R, not S. Error in movie
R,RR,R, error in movie which said R, S.
This one is very hard.But for each of the 5 chiral C's, the tie-breaking processes do work.
2 B. Identify each of the following molecule as chiral or achiral. (By circling the chiral ones.) Write “meso” where it applies. (In other words, if it is achiral despite having chiral centers).
31.
32.
33.
34.
35. 36.
37.
38. 39.
40.
41.
42. 43.
44.
45.
46.
47. 48.
49.
50.
51. 52. 53.
NH
O
CH3HNH2
OHHHO OH
OHH
O
HH3CO HH3CO
CH3H
HH3C
OHH
OHH O
Cl ClHH Cl HH
Cl
ClH
HCl
ClH
ClH
Cl ClHH Cl BrH
H
OH
OH
OH
OH
OH
CH3
OH
HOHH
OH
OHHH
Cl
CH3
H
Cl
CH3
HCl
CH3
H
H
CH3
ClCl
CH(CH3)2
H
Cl
CH3
H
T
One chiral carbon => chiral molecule
Two common attachments => achiral
Plane of symmetry => achiral
Problems 51-53, in which you need to translate from a Newman projection, are on the very very difficult end. If you want to challenge yourself, do them. But these are probably harder than you'll see on the test.
3
C. Mark the relationships between the following structures as either “same”, “enantiomers”, or “diastereomers”.
54.
55.
56.
57.
58.
59.
60.
61.
62. 63.
64.
65.
66.
67.
68. 69.
70.
71.
72. 73.
74. 75.
76. 77.
ClHClH
ClH Cl H
ClH HCl ClH H Cl
ClHCl
HH3C ClHCl H
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OHOH
OH
OHOH
OH
OHOH
OH
OHOH
OH
OHOH
OH
OHOH
OH
OHOH
OHOH
HOOH
OH
OHOH
ClH
ClH
HCl
HCl
ClH
ClH
HCl
ClH
ClH
HCl
HCl
ClH
Cl ClHH
ClH
HCl
Cl HHCl
ClH
HCl
Cl HHCl
ClH
HCl
OH
OH
OH
HOHH
OH
OHHH OH
OH
Cl
CH3
H
Cl
CH3
HCl ClH
HCl
CH3
H
H
CH3
Cl ClH
ClH
With just one chiral C, if you can assign R/S for both, you can tell if same or different.
64 + 66have some tricky "turning-them-over" issues. Don't worry about them.