1 show how the following compounds can be synthesized
a) Fist step: the compound acts as an amine hence its formation will rely on the alkylation of ammonia hence the formation of amine is the first step. This is formed through reaction of a phenyl halide with ammonium ion carrying lone pair. The ammonium (NH3) acting as a nucleophile, substitutes the halide thereby leading to the formation of a phenyl amide.
NH3 + C6H11Cl C6H11NH2
Second step: addition reaction whereby there is addition of carbonic acid
C6H11NH2 + HCO3 C6H11NH2CO2H
b) Synthesis of nitrophenol
Phenol is passed through 20% concentrated nitric acid.
c) Synthesis of 2, 4, 5-nitro-benzoic acid
Nitration of the aromatic ring forming methyl 3-nitrobenzoate
The released heat is cooled with H2SO4
for the formation of the final 2, 4, 5-nitro-benzoic acid, there is continuous nitration of the solution.
Problem 4.6: predict the product of the following reactions
a)
O O
b)
O
Problem 4.7: Write equation for the Diels-Alder synthesis of the following compounds
Problem 12.1: What products would you expect from the following reactions?
a)
CH3
CH3 CH CHO
b)
Problem 12.9: The dimerization of cyclopentadiene also occurs in an endo way.
a) Show how this happens
The graph shows how the endo way for the dimerization as the product of dimerized cyclopentane is formed at a low temperature than the original cyclopentane
b) Which pie electron interact
2 π electron donor
c) What is the three dimensional structure of the product
Three dimensional dimension
Q 4.) Answer the following:
i) Show all steps in the Aldol condensation reaction when butanal is treated with base
Step 1: additional phase
The base will function in removing the acidic hydrogen from because it is nucleophile. This results to a reactive enolate
Step 2: The enolate then attract electrons from the formed butanone from the electrophyklic carbonyl c. this results to the formation of alkoxide
Step 3: this again presents a step for acid-base reaction. The alkoxide acts in removing protons from the provided butanal thereby resulting to hydroxyaldehydes which acts as the aldol.
ii) Show all steps in the synthesis of 2-methylbutanoic acid starting with diethyl malonate
Step 1: converting diethyl malonate to enolate anion
This is done with ethoxide put inside ethanol as shown in the following reaction
Step 2: SN2 reaction through the use of alkyl halide
In this step, the enolate ion formed in the first step undergoes SN2 reaction resulting to formation of a mono-alkylmalonic ester. The arrows shows the action of the nucleophile on the electrophiles
(where R represents the methyl)
Step 3: acidic hydrolysis of the diester the acid
This is the final step which involve the b-carboxylic acid undergoing decarboxylation because of their stability in the acidic solution thereby giving out the acid-enol. The isomerization of the acid enol gives the 2-methyl butanoic acid.
(where R represents the methyl)
iii) Propose a step by step mechanism to predict the product formed in the following Robinson Annulation reaction.
Step 1: Michael Addition
The OH- attracts the hydrogen atoms in the l ring thereby adding to the addition of a inner ring to the phenyl.
Step 2: aldol addition
This involves condensing formed ring of phenyl with the entire oxygen atom removed.
Problem 19.16: Outline all steps in a malonic ester synthesis of each of the following
Pentanoic acid
Materials: ester
Step 1: deprotanation of ester to form enolate
The CH3O will be acting as a base in order to remove the many acidic proton thereby resulting into enolate
Step 2: SN2 of the enolate upon an pentyl halide, forming a new C-C bond
In this step there is need for a nucluephile (enolates) in order to form the new C-C bond
Step 3: acidic hydrolysis of the formed ester to give a pentanoic acid
In this step there is addition of acid and water in order to offer the aqueous hydrolysis of the ester to deliver a pentanoic acid
Problem 19.8: Show how you would use the acetoacetic ester synthesis to prepare each of the following
a) 2-pentanone
Materials : Na+ -OEt and H3O+ , heat
Equation O O O
CH3CH2Br + EtOCCH2CCH3 CH3CH2CH2CCH3 ( 2-Pentanone)
b) 3-propyl-2-hexanone
The reaction occurs in presence of Na+ -OEt and H3O+ , heat
CH3CH2(C3H7)CH2Br + EtOCCH2CCH3 CH3CH2CH(C3H7)CCH3
c) 4-phenyl-2-butanone
O O
CH3Br + EtOCCH2CCH3
