Exercício de Química Sintética e Organica Mista (444)

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(h) Cyclic acetal formation occurs when aldehydes react with ethylene glycol.
(i) Aldehydes react with primary amines to yield imines.
( j) Secondary amines combine with aldehydes to yield enamines.
(k) Oximes are formed on reaction of hydroxylamine with aldehydes.
(l) Hydrazine reacts with aldehydes to form hydrazones.
(m) Hydrazone formation is the first step in the Wolff–Kishner reduction (Section 12.8).
(n) The reaction of an aldehyde with p-nitrophenylhydrazine is analogous to that with hydrazine.
H2O�
Propanal Propanal
p-nitrophenylhydrazone
CH3CH2CH NNH NO2CH3CH2CH
O
�
p-Nitrophenylhydrazine
O2N NHNH2
CH3CH2CH NNH2
Propanal hydrazone
N2�CH3CH2CH3
Propane
NaOH
triethylene glycol, heat
CH3CH2CH
O
Propanal
CH3CH2CH NNH2
Propanal hydrazone
H2NNH2
CH3CH2CH
O
Propanal
CH3CH2CH NOH
Propanal oxime
H2NOH
� (CH3)2NH
Dimethylamine 1-(Dimethylamino)propene
CH3CH CH
N(CH3)2 O
CH3CH2CH
Propanal
p-toluenesulfonic acid
benzene
�H2O
� C6H5NH2
Aniline N-Propylideneaniline
CH3CH2CH NC6H5
O
CH3CH2CH
Propanal
�
p-toluenesulfonic acid
benzene
HOCH2CH2OH
Ethylene glycol
O
CH3CH2CH
Propanal 2-Ethyl-1,3-dioxolane
CH2CH3H
O O
ALDEHYDES AND KETONES: NUCLEOPHILIC ADDITION TO THE CARBONYL GROUP 439