Q. Which of the following compounds would be the main product of an aldol condensation of acetaldehyde and acetone?
A) $CH_{3}CH = CH.CHO$
B) $CH_{3}CH = CHCOCH_{3}$
C) $\left( CH_{3} \right)_{2}C = CH.CHO$
D) $\left( CH_{3} \right)_{2}C = CHCOCH_{3}$
Explanation
(b)
$CH_{3}CHO + HCH_{2}COCH_{3}\overset{\ \ NaOH\ \ \ \ \ }{\rightarrow}$
$CH_{3}CH(OH)CH_{2}COCH_{3} + CH_{3}CH(OH)CH_{2}CHO$
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \$major
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$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ + \left( CH_{3} \right)_{2}C(OH)CH_{2}COCH_{3}$
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ + \left( CH_{3} \right)_{2}C(OH) - CH_{2}CHO$
$CH_{3}CH(OH)CH_{2}COCH_{3}\underset{{- H}_{2}O}{\overset{\ \ \ \ \ \ \ \mathrm{\Delta}\ \ \ \ \ \ \ }{\rightarrow}}CH_{3}CH = CHCOCH_{3}$
major product major product(25%)
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.