Name ____________________________
Chem 7A
Quiz 2
1) Number the groups in the following set from highest (1) to lowest (4) priority using the R/S convention. (1 pt)
_______
_______
_______
_______
2) Label the R or S configurations of all stereocenters in each of the following: (1 pt each)
3) What is the maximum possible number of stereoisomers for the following molecule? (1 pt)
__________
4) How many stereoisomers are possible for each of the following molecules?
a) (1 pt)
_______
b) (1 pt)
c) (1 point extra credit)
_______
1
_______
5) Circle the molecules that are chiral. There may be more than one. (1 pt)
6) A mixture of enantiomers was found to have a [ ]D = +2.7. The pure (+) enantiomer has a [ ]D = +4.5. What
percentage of the sample is made up of the (+) enantiomer? (1 pt)
7) (R)-2-bromobutane is subjected to radical chlorination. How many different monochlorination products are
possible (both structural and stereoisomers) and how many distinct boiling points would they have? (2 pts)
Total # of monochlorination products _________
Total # of boiling points _________
8) Number each of the following in order of their nucleophilicity from best (1) to worst (5). (1 pt)
OH-
CH3OH2 +
_______
_______
H2 O
NH3
NH2 -
_______
_______
_______
9) Number each of the following in order of their nucleophilicity in a polar protic solvent from best (1) to worst (4).
(1 pt)
NH3
H2 O
PH2-
NH2 -
_______
_______
_______
_______
2
10) Circle the reaction that would proceed the fastest by an SN 2 mechanism? All are performed at the same
temperature and in the same solvent. (1 pt)
a)
CH3CH2 CH2 Cl + OH-
b) (CH3)2 CHCl + OH-
c)
CH3CH2 CH2 Cl + H2O
d) (CH3)2 CHCl + H2 O
11) Number each of the following in order of their SN 2 substrate reactivity from fastest (1) to slowest (4). (1 pt)
_______
_______
_______
_______
12) What is the most likey mechanism for each of the following reactions (SN 2, SN 1, or no reaction)? For the
reactions that occur, draw and name all organic products. (1 pt each)
RXN type
a)
________
b)
________
c)
________
d)
________
3
13) Draw a correct structure or provide a correct name for each of the following: (1 pt each)
a) (2R,3S)-1,2,3-trichloropentane (C2-C3 Newmann)
b)
Common: ________________________________(1 pt)
IUPAC: __________________________________(1 pt)
c)
d) meso-1,3-dichlorocyclopentane
14) For each pair of molecules, indicate whether the two molecules are identical, structural isomers, enantiomers or
diastereomers. (1 pt each)
4