CHEMISTRY 211 Exam 2 Monday, October 19, 2009. Answer Key. Answer all 19
questions (150 pts). 1. (10) From the list below, state whether each species ...
CHEMISTRY 211
Exam 2
Monday, October 19, 2009
Answer Key
Answer all 19 questions (150 pts). 1. (10) From the list below, state whether each species shown is an electrophile or nucleophile. a)
Br2
electrophile
b)
Me2BH
c)
electrophile
KNO3
d)
nucleophile
HF
electrophile
e)
LiOCOCH2CH3 nucleophile
2. (12) Give IUPAC names for the molecules shown below [in part a) only, include E or Z as appropriate]. a)
b)
(Z) 4-isopropyl-3,5,6-trimethyl-3-octene
3-ethyl-2-isopropyl-1-methyl-1-cyclobutene
3. (8) For each of the reactions shown below, indicate whether the overall process is a Markovnikov or anti-Markovnikov addition. Note: you may not have seen the reaction before. b)
a)
H H CHO
SeCH3
Markovnikov
anti- Markovnikov
4. (6) State whether each of the following reactions is an addition, rearrangement, elimination or substitution.
5. (6) Circle any of the following that represent a cis isomer.
6. (8) For each of the reactions shown below, indicate whether the overall process is a Syn or Anti addition. Note: you may not have seen the reaction before. a)
Br H
b) HO
Br
OH
Br CH3
SYN
Br
ANTI
7. (42) In each of the following reactions, either reactants or products are missing. Fill in the blanks with the appropriate molecules. If more than one step is involved, indicate this by using 1)......; 2)....... Show the stereochemistry of the products, as appropriate.
8. (6) In each example below, identify the nucleophile and the electrophile for the reactants.
9. (6) Circle any of the molecules shown below that can exist as an (E) or (Z) isomer.
10. (7) A molecule with 5 degrees of unsaturation could contain which of the following? Circle all which apply. a) 1 ring and 4 double bonds e) 5 double bonds
b) 5 rings
c) 3 rings
f) 1 triple bond and 2 double bonds
d) 5 triple bonds
g) 1 ring and 2 triple bonds
11. (9) For the following, circle all of the statements to the right which are correct as shown.
12. (2.5) True or False? An anti addition to an alkene could give a trans product. 13. (2) True or False? A hydrogen attached to a carbon of a triple bond can be abstracted using a base, the conjugate acid of which is weaker than the alkyne. 14. (3) Which of the following alkenes is the most stable?
15. (4) How many degrees of unsaturation are there in C6H5NBrFO? You need not show your work. Four Degrees of Unsaturation 16. (3) A compound X (C9H16) reacts with O3 followed by Zn to yield the two fragments below. What is the structure of X?
17. (2.5) What is the general formula for a cycloalkene? a) CnHn
b) CnH2n
c) CnH2n+2
d) CnH2n-2
18. (8) Show an arrow (or arrows) indicating the movement of electrons (sharing) between each of the reaction pairs shown. You need not show the consequence of your arrows.
19. (5) By assigning priorities to the groups attached, designate either E or Z (as appropriate) to the molecule shown. You must show all the priorities (#1 = highest) to receive full credit.
