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Prévia do material em texto

CHAPTER 21 857 
 
 
21.33. 
(a) The product is a methyl ketone that has the following 
(highlighted) group connected to the  position: 
 
 
 
This group can be installed via an acetoacetic ester 
synthesis, using the following alkyl halide: 
 
 
 
An acetoacetic ester synthesis begins with the 
deprotonation of ethyl acetoacetate (using ethoxide as a 
base). The resulting resonance-stabilized conjugate base 
is then treated with the alkyl halide above, thereby 
installing the alkyl group. Subsequent hydrolysis and 
decarboxylation give the product, as shown: 
 
 
 
(b) The product is a methyl ketone that has the following 
two (highlighted) groups connected to the  position: 
 
 
 
Each of these groups can be installed via an acetoacetic 
ester synthesis, using the following halides: 
 
 
 
An acetoacetic ester synthesis begins with the 
deprotonation of ethyl acetoacetate (using ethoxide as a 
base). The resulting resonance-stabilized conjugate base 
is then treated with one of the halides above, to install 
one of the two groups. The other group is installed in a 
similar way (deprotonation with a base, followed by 
alkylation). Subsequent hydrolysis and decarboxylation 
give the product, as shown: 
 
OEt
O O
O
1) NaOEt
2) EtI
3) NaOEt
4) PhCH2Br
5) H3O+, heat1) NaOEt
2) EtI
OEt
O O
1) NaOEt
2) PhCH2Br OEt
O O
H3O+, heat
 
 
 
(c) The product is a methyl ketone that has the following 
two (highlighted) groups connected to the  position: 
 
 
 
Each of these groups can be installed via an acetoacetic 
ester synthesis, using the following alkyl halides: 
 
 
 
An acetoacetic ester synthesis begins with the 
deprotonation of ethyl acetoacetate (using ethoxide as a 
base). The resulting resonance-stabilized conjugate base 
is then treated with one of the alkyl halides above, 
thereby installing one of the two alkyl groups. The other 
alkyl group is installed in a similar way (deprotonation 
with a base, followed by alkylation). Subsequent 
hydrolysis and decarboxylation give the product, as 
shown: 
 
 
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