Organic Chemistry

Problems 833

glycolysis (p. 826)
haloform reaction (p. 796)
Hell–Volhard–Zelinski (HVZ) reaction
(p. 796)
Hunsdiecker reaction (p. 820)
(p. 788)
keto–enol interconversion (p. 792)

a-hydrogen

keto–enol tautomerization (p. 792)

ester (p. 791)

Kolbe–Schmitt carboxylation reaction

(p. 801)

malonic ester synthesis (p. 821)

Michael reaction (p. 804)

mixed aldol addition (p. 809)

b-keto

mixed Claisen condensation (p. 812)

Robinson annulation (p. 817)

reaction (p. 793)

Stork enamine reaction (p. 805)

tautomers (p. 791)

a-substitution

Problems

44. Write a structure for each of the following:

a. ethyl acetoacetate

b. acid

c. a ester

d. the enol tautomer of cyclopentanone

e. the carboxylic acid obtained from the malonic ester synthesis when the alkyl halide is propyl bromide

45. Give the products of the following reactions:

a. diethyl heptanedioate: (1) sodium ethoxide; (2) HCl

b. pentanoic acid , followed by hydrolysis

c. acetate: (1) sodium ethoxide; (2) HCl

d. diethyl 2-ethylhexanedioate: (1) sodium ethoxide; (2) HCl

e. diethyl malonate: (1) sodium ethoxide; (2) isobutyl bromide; (3) HCl,

f. carbonate: (1) sodium ethoxide; (2) HCl

g.

h.

i. cyclopentanone: (1) (2) ethyl bromide; (3) HCl,

j. in THF followed by methyl iodide

k.

l. in

m. diethyl (1) excess sodium ethoxide; (2) HCl

46. The chemical shifts of nitromethane, dinitromethane, and trinitromethane are at and Match each chemical
    shift with the compound. Explain how chemical shift correlates with


47. a. Explain why a racemic mixture of 2-methyl-1-phenyl-1-butanone is formed when (R)-2-methyl-1-phenyl-1-butanone is
    dissolved in an acidic or basic aqueous solution.
    b. Give an example of another ketone that would undergo acid- or base-catalyzed racemization.


48. Identify A–L. (Hint:A shows three singlets in its spectrum with integral ratios and gives a positive iodoform test;
    see Section 19.4)
    
    
    1. CH 3 O−
    
    
    2. CH 3 Br
    
    
    
    

∆

HCl, H 2 OHO− H 3 O+

A ∆

C 5 H 8 O 3

BCD

∆

HCl, H 2 O

HO−

excess

I 2

excess

SOCl 2

EH

1. CH 3 O−


2. CH 3 Br

∆

HCl, H 2 O

FG

2. HCl


3. CH 3 O−
   IJ L

CH 3 OH

K

(^1) H NMR 3:2:3
pKa.
d 6.10,d 4.33, d 7.52.
1,2-benzenedicarboxylate+ethyl^ acetate:
cyclohexanone+NaOD D 2 O
2,7-octanedione+sodium^ hydroxide
g-butyrolactone+LDA
pyrrolidine+catalytic H+; H 2 O
dibenzyl ketone+methylvinyl ketone+excess sodium hydroxide
1,3-cyclohexanedione+allylbromide+sodium hydroxide
acetophenone+diethyl
H 2 O+¢
acetone+ethyl
+PBr 3 +Br 2
b-keto
a-methylmalonic