Organic Chemistry 1st Exam. Oct 21, 2004
1.Nomenclature. Give the correct IUPAC name or structure for the following.(20)
(A) │ (B) ╴ (C)
／╲╱╲╱╲╱╲╱ Br▃／ ＼﹍╱ ／＼╴／＼
｜ ╲╴／ \╴/ ╲／
／╲
(D) ／＼ (E) ｜＼ (F) ╱╲╱╲
／￣￣＼ ｜ ＼ ｜ ｜
＼╴╴／ ／￣｜￣￣╲ ◤╲╱╲╱◥F
／ ｜ ╲
￣￣￣ ╲ ／
＼ ／
(G) trans-Decalin
(H) 5,8-bis(1-methylethyl)dedecane
(I) 6-(2-chloro-2,3,3-trimethylbutyl)undecane
2.Sulfuryl chloride(SO2Cl2) can be substituted the chlorine gas for the
chlorination of methane with the formation of SO2 as by product(equation
below).
hν
CH4 + SO2Cl2 ────→ CH3Cl + SO2 + HCl
Propose a reaction pathway leading to the formation of CH3Cl.(8)
3.Please draw all possible staggered and eclipsed conformations(in Newman
projection) with respect to C3-C4 of 2,2,4-trimethylpentane. Arrange the
relative stability of these conformers in order.(16)
4.Please arrange the relative stability of radical species in order. Please
explain why?(6)
╱╲‧ ／╲‧ ‧CH3 │
∣ ∣ ─┤‧
╲╱ │
5.For the photochemical halogenations of A, which of the following reagent
would give the mono-substituted product in the highest selectivity? Please
draw the structure of the resulting product.(5)
＼／＼／
｜ ╱╲ F2 , Cl2 , Br2 , I2
A
6.Find the isoprene units in each of the following molecules.(5)
╲╱ ╴ ╴
＼﹍／￣＼▂ ／＼／￣╲╴／￣＼╴／＼
／ ＼╴／ ｜ ∥ ／￣ ／￣ OH
◢ ╲／╲
HO Methanol Vitamin A
7.Draw the most stable conformation of trans-1-chloro-4-isopropylcyclohexane;
then flip the ring and redraw the chair conformer. Accordingly, estimate the
energy difference between the two chair conformation isomers. Calculate the
ratio of the two at 300K. (10)
8.Draw the Newman projection of methylcyclohexane showing the methyl group
being at axial position. (5)
9.Characterize the following species as either Nucleophile or electrophile. (5)
H+ , NH3 , AlCl3 , Li+ , CN- .
10.Draw all resonance structures of nitrate. (6) [Lewis structure]
11.What are the "angle strain" and "torsional strain" in cyclopropane? (8)
12.Give three possible products from the pyrolysis of octane. Showing the
pathways leading to these products. (6)
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