wiz-icon
MyQuestionIcon
MyQuestionIcon
2
You visited us 2 times! Enjoying our articles? Unlock Full Access!
Question

Malonic ester contains an active methylene group and two hydrogen atoms of active methylene group which are easily replaced by alkyl and acyl groups in the presence of a strong base. The carbonation intermediate formed makes SN2 attack on alkyl or acyl groups. In the sequence of reactions given above, the final product [S] is :

44850_c5d79c5b08764b75b3637a07326c918e.png

A
CH2=CHCH2CH2COCOOH
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
CH2=CHCH2COCH2COOH
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
CH2=CHCH2CH2COOH
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
CH3CH=CHCH2COOH
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is C CH2=CHCH2CH2COOH
Sodium hydride abstracts the proton from the active methylene group of diethyl malonate to obtain the carbanion [P]. This acts as a nucleophile and attacks 1-chloro pop-1-ene. Chloro group is replaced in SN2 mechanism to obtain [Q]. The ester groups are hydrolyzed in presence of acid to obtain [R].
This is followed by thermal decarboxylation to obtain [S]. Thus [S] is CH2=CHCH2CH2COOH
131067_44850_ans_10d32256894f49ec9c467c5b930e72b0.png

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Decarboxylation
CHEMISTRY
Watch in App
Join BYJU'S Learning Program
CrossIcon