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2003/ 1/16
Total:106%
I)Simple choice(only one correct answer for each question):3%*20=60%
1)Concerning the products of the catalytic hydrogenation of the following
compounds A,B,C and D, which statement is corect?
◥__ ◥__ '.__ '.__
∕ \\__ ∕ ﹨╴ ∕ ﹨__ ∕ ﹨╴
﹨__∕ ﹨__∕￣ ﹨__// ﹨__∕￣
◢ I .' II ◢ III .' IV
(A)I gives a single stereoisomer, II and III yield the same products.
(B)I and IV give a single diastereoisomer, II and III yield a mixture of
two diastereomers.
(C)All of them give a mixture of enantiomers.
(D)I and IV give a mixture of diastereomers, II and III yield a single
stereoisomer.
2)What is the final product of the following synthesis?
H3
HO C H
H2/Ni2B (1)OsO4 ﹨:◢
CH3C≡CCH3 ───→────→ (C) | (其餘選項略)
(2)NaHSO3 ∕:◥
HO C H
H3
3)What product would you expect from the following reaction?
D BD2 H CH3 H CH3 H CH3
╱╲ (1)(BD3)2 ◥ ◤ ◥ ◤ ◥ ◤ ◥ ◤
\╴/ ─────→ H…─…CH3 H…─…D D…─…OH HO…─…D
￣\ (2)H2O2/OH¯ / \ / \ / \ / \
CH3 ＼／ ╲╱ ╲／ ╲／
I II III IV
(A)I+enantiomers (B)II+enantiomers (C)III+enantiomers (D)IV+enantiomers
4)Select the best sequence of steps for performing the following
transformations:
╴ ? ╴
∕￣﹨╴CHCH3 ─→ ∕￣﹨╴CHCOOH
\\__// | \\__// |
Br Br
(A)1.NaOCH2CH3/ethanol.△; 2.KMnO4/OH¯; 3.H﹢
(B)1.NaOCH2CH3/ethanol.△; 2.O3,then Zn(OAc)2; 3.H2SO4; 4.H2O
(C)1.NaOCH2CH3/ethanol.△; 2.B2H6; 3.H2O2/OH¯; 4.NaIO4, RuCl3
(D)1.NaOCH2CH3/ethanol.△; 2.Br2/CCl4; 3.NaNH2/NH3,then H2O;4.H2O,H2SO4,HgSO4
5)When the addition of IBr to 3-methyl-2-pentene forms the product predicted
by Markovnikov's rule, that occurs because
(A)Steric hindrance favors its formation (B)The product is statistically
favored (C)It depends on the catalyst used (D)It is formed via the more/most
sable carbocation
6)Which of the following statements on nucleophilic substitution reaction is
FALSE?
(A)Primary alkyl halides react slower than the corresponding secondary
substrates in the SN1 reaction
(B)The rate of reaction depends on the nature of the leaving group in both
SN1 and SN2 reactions
(C)In the SN1 reactionm a carbocation transition state is formed
(D)In the reaction of CH3I with (CH3)2NH, the rate in ethanol solvent is
faster than that in hexane
7)The optically pure tosylate of 2,2-dimethyl-1-phenyl-1-propanol ([α]D=
-30.3。) is heated in acetic acid to yield the corresponding acetate ([α]D
=+5.3。). If complete inversion had occurred, the optically pure acetate
would have had [α]D=+53.6。.
(結構圖略)
Which of the following statements is FALSE?
(A)9.9% of the original tosylate was inverted
(B)54.9% of (+)-product
(C)45.1% of (-)-product
(D)The reaction apparently occurs via both SN1 and SN2 mechanism
8)about an INVERSION of the configuration at the stereocenter carbon?
9)In the reaction of 2-bromobutane with 2-aminobutane, which of the following
statements is True?
(A)The rate of (S)-2-bromobutane with (R)-2-aminobutane equals to the rate
of (R)-2-bromobutane with (R)-aminobutane
(B)The rate of (S)-2-bromobutane with (S)-2-aminobutane equals to the rate
of (R)-2-bromobutane with (R)-aminobutane
(C)The rate of (S)-2-bromobutane with (S)-2-aminobutane equals to the rate
of (R)-2-bromobutane with (S)-aminobutane
(D)The products from the of (R)-2-bromobutane with (S)-2-aminobutane and
form the reaction of (S)-2-bromobutane with (R)-aminobutane are
adiastereomeric isomers
10)Which is the strongest nucleophile for an SN2?
(A)OH- (B)CH3CH2O- (C)CH3C(=O)O- (D)CF3C(=O)O-
11)Which of the following statements concerning the electrophilic addition to
a carbon-carbon double or triple bond is FALSE?
(A)The orientation of the addition reactions follows the Markovnikov's rule
with nucleophile adds to more substituted carbon atom and electrophile
to less substituted carbon atom
(B)In the addition of bromine to propene, one of the bromine atom is
considered as an electrophile and the other as a nucleophile
(C)Since alkyne has two π-bonds, the electrophilic addition reaction to
propyne is faster than that to propene
(D)A cation internediate is normally involved in the electrophilic addition
to an alkene
12)Which of the following reactions foes NOT give the indicated product?
H3C 1)BH3 H3C H3C Br2/H2O H3C
(A) ╲╱╲ ────→ ◥╱╲ (B) ╲╱╲ ───→ ◥╱╲
\\__/ 2)H2O2/OH- \__/ \\__/ Br﹉\__/
.' ◢
HO HO
H3C HBr/△ H3C
(C) ╲／╲ ──────→ ＼／＼ A mixture of cis- and trans- product
\\__/ O-O \__/
/ \ Br﹋
Ph─ ─Ph
\\ //
O O
H3C OsO4 H3C
(D) ╲╱╲ ──→ '.╱╲
\\__/ HO￣\__/
/
HO
13)Compound A has the formula C8H12 and is optically active. It reacts with
hydrogen in the presence of platinum metal to give B, which has the formula
C8H18 and is optically inactive. Careful hydrogenation of A using Lindlar
catalyst(Pd/BaSO4/quinoline/S) gives C, which has the formula C8H14 and is
optically active. Compound A reacts with sodium in ammonia to give D which
also has the formula C8H14 and is optically active. What is compound A?
(D) ╱ (餘選項略)
///
\\╱╲╱
｜
14)判斷halide加成的transformation reaction(略)
15)Which of the following reactions give the product, which is a meso compound
?
(A)H3C Ph H2/Pd/C (B)H3C Ph CF3CO3H
\╴/ ───→ \╴/ ───→
/￣\ /￣\
Ph CH3 Ph CH3
(C)H3C Ph Br2 (D)H3C Ph OsO4
\╴/ ─→ \╴/ ──→
/￣\ /￣\
Ph CH3 Ph CH3
16)Which of the following reaction schemes does NOT afford adipic acid,
H2O(CH2)4CO2H, a useful starting material for nylon 66?
(A) HBr OH- KMnO4 (B) ╱＼ Br2 KO'Bu KMnO4
\\╱╲╱\\ ───→─→──→ ︱ ∣─→──→──→
peroxide ╲／ hv
(C) O3 KMnO4
\\╱╲╱╲╱\\ ─→──→ (D) Non of the above
17)Which of the following transformations would occur readily?
(A)┌O Dilute HCl in MeOH
└┼Me ─────────→ MeOCH2CH2CMe2OH
Me
__ Me Me
(B) / \__| KOEt /￣\╴/
╲／ C-Br ──→ ╲／ \\
| ╱╲
╱╲ \__/
\__/
(C) /￣\╱ /￣\__ /￣\╱ /￣\
\__/╲ + \__/ Cl → \__/￣O￣\__/ + NaCl
ONa
(D) (太難畫 總之它不是答案)
18)What would you obtain from the following reaction sequence?
isobutylene HC≡CNa H2/Pd/BaSO4/quinoline HBr/peroxide
Br(CH2)8OH ─────→───→──────────→──────→
H+
(A)Br(CH ) OC(CH ) (B)H C=CH(CH ) Br (C)CH (CH ) OC(CH ) (D)(CH ) C(CH ) Br
2 10 3 3 2 2 8 3 2 9 3 3 3 3 2 8
19)一樣是halide的加成 (略)
20)steric compound加NaOEt之後的產物 (略)
II)Please propose a reasonable mechanism to account for the formation of the
two products(Use curves to show electron flow) (10%)
H OH CH3 CH3
╱╲|／ H+ ╱╲／ ╱╲╴/
｜ | ─→ ︱ ∥ + \__/￣\
╲／|╲ heat ╲／╲ CH3
CH3CH3 CH3
III)Explain how polar aprotic solvents affect reaction rates of SN1 and SN2
reactions (6%)
IV)Explain the following terms and give one representative example to
illustrate your points (4%*3=12%)
(A)regioselective reactions (B)stereospecific reactions
(C)Hammond-Leffler Postulate
V)給3個reaction mechanisms決定Caryophylene(C15H24)的結構
VI)Showing reaction mechanisms for the following reactions (3%*4=12%)
(A)epoxidation of alkene with organoperoxide
(B)ozonolysis of alkene in the presence of peroxide
(C)hydrobromination of alkene in the presence of peroxide
(D)chlorination of alcohol with thionyl chloride
Have A Great Winter Break!!!
Happy Chinese Lunar Year!!!
選擇題解答:DCDAD DAEBB CBDDC DBADB
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