課程名稱︰有機化學二
課程性質︰必修
課程教師︰羅禮強
開課系所︰化學系
考試時間︰May 18,2006
是否需發放獎勵金：否
（如未明確表示，則不予發放）
試題 :
Part 1 單選題,共十題(每題達對3分,不答0分,答錯扣0.75分)
1.In the mechanism for the acid catalyzed hemiacetal formation,the first step
is? (a)protonation of the carbonyl oxygen
(b)nucleophilic attack at the carbonyl carbon
(c)nucleophilic attact at the carbon of the alcohol
(d)protonation of the oxygen of the alcohol
(e)elimination of a water molecule
2.What Grinard reagent and catbonyl compound react to give benzyl alcohol
after treatment with aqueous acid?
(a)phenyl magnesium bromide and formaldehyde
(b)phenyl magnesium bromide and ethylene oxide
(c)benaldehyde and ethyl magbesium chloride
(d)benaldehyde and methyl magbesium chloride
(e)acetophenone and methyl magbesium chloride
3.An acetal is used to protect aldehyde.What class of compound most closely
resembles an acetals in its reactivity with CH3MgBr?
(a)aldehydes
(b)ketones
(c)ethers
(d)alcohols
(e)thiols
4.The mechanism of saponification is:
(a)nucleophilic aromatic substitution.
(b)nucleophilic acyl substitution.
(c)electrophilic acyl substitution.
(d)Sn2
(e)Sn1
5.In a carbonyl group
(a)the oxygen acts as a Lewis acid.
(b)the C=O bond length is shortened due to resonace.
(c)the carbon is sp3 hybridized.
(d)the carbon carries a partial negative charge.
(e)the carbon is electrophilic and the oxygen is nucleophilic.
6.Which of the following aldehyde can exist in equilibrium with a cyclic
hemiacetal?
(a)4-pentenal
(b)3-hydroxypropanal
(c)2-hydroxybutanal
(d)3-hydroxybutanal
(e)4-hydroxybutanal
7.What is the name of molecule having the formula , CH3CO2CH(CH3)2
(a)ethyl acetate
(b)propyl acetate
(c)Isopropyl ethanoate
(d)ethyl propanoate
(e)dimethyl acetate
8.The mechanism for both the Clasisen condensation and the base catalyzed Aldol
condensation share what common step(s)?
(a)base removal of an α-hydrogen
(b)nucleophilic addition of the enolate to the carbonyl group of another
molecule
(c)addition of an acid to regenerate the ester
(d)(a) and (b) only
(e)none of the above
9.What statement is False relative to nucleophilic addition?
(a)When a weak nucleophile is present,the reaction can be catalyzed by acid
(b)The nucleophile attacks the trigonal carbon of the carbonyl group
(c)Ketone are more reactive than aldehyde
(d)Nucleophiles that add irreversibly are poor leaving groups.
(e)Nucleophiles can be classified as those that add reversibly to carbonyl
compounds and those that add irreversibly
10.The boiling point of propanoic acid is higher than that of 1-butanol because
(a)propanoic acid has a higher molecular weight than 1-butanol
(b)propanoic acid is more soluble in water than 1-butanol
(c)propanoic acid is a better hydrogen bond donor than 1-butanol
(d)propanoic acid forms hydrogen bonded dimmers and 1-butanol does not
(e)1-butanol forms hydrogen bonded dimmers ad propanoic acid does not
Part 2 問答題(共85分)
1.Please describe what you can do to control a reaction temperature at -78'c
(10 point)
2.Bearing in mind the principle of micrescopic reversibility,write the
mechanism for the reaction shown below(10 points)
ꄠ O
H⊕ ∥
C6H5CO2H + (CH3)3COH ──→ C6H5-C-OC(CH3)3
3.Please draw a structural formula of the principal product formed when ethyl
benzoate is treated with each reagent.(10 point)
(a)H2O,NaOH,heat
(b)DIBALH(-78'C),then H2O
(c)LAH,then H2O
(d)C6H5MgBr(two equivalents),then HCL/H2O
(e)CH3CH2CH2NH2,heat
4.Propose a mechanism for the following reaction(10 point)
O O
∥ ∥ CL
╱╲ CH3COOH ╱╲／
∣ ∣ +CL2 ───→ ｜ ｜ + HCL
╲／ ╲／
5.Please perform retro-synthetic analysis for the following target molecul.You
may use acetone,ethyl acetate and any other reagents no more than 3 carnon
(25 point)
O
∥
╱╲
╲| ∥
╱╲／╲
6.The following isomerization illustrates the reversibility or the Dieckmann
condensation.
(a)What starting material will lead,upon reaction under Dieckmann condition
, compound A.
(b)Please suggest a mechanism for the conversion of A to B(20 point)
CO2ET + O
\/ O NaOEt H3O ∥ CO2Et
╱╲// ───→──→ ╲╱╲╱
∣ ∣ Xylene ∣ ∣
╲╱ ╲／
A B
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