Solution Found!
For each of the following compounds, indicate the aldehyde
Chapter 18, Problem 21P(choose chapter or problem)
For each of the following compounds, indicate the aldehyde or ketone from which it would be formed by an aldol addition:
a. 2-ethyl-3-hydroxyhexanal
b. 4-hydroxy-4-methyl-2-pentanone
c. 2,4-dicyclohexyl-3-hydroxybutanal
d. 5-ethyl-5-hydroxy-4-mcthyl-3-heptanone
Questions & Answers
QUESTION:
For each of the following compounds, indicate the aldehyde or ketone from which it would be formed by an aldol addition:
a. 2-ethyl-3-hydroxyhexanal
b. 4-hydroxy-4-methyl-2-pentanone
c. 2,4-dicyclohexyl-3-hydroxybutanal
d. 5-ethyl-5-hydroxy-4-mcthyl-3-heptanone
ANSWER:
Solution 21P
Aldol condensation: In the presence of a strong base, aldehyde or ketone reacts with one another or each other to gives -hydroxy aldehyde or ketone on further dehydration forms
–unsaturated aldehyde or ketone.
Aldol reaction is a reversible reaction, when aldol product is heated with hydroxide ion and water, reactants can be regenerated. This is known as retro-aldol addition.
(a)
When 2-ethyl-3-hydroxyhexanal is heated in the presence of base retro-aldol addition reaction takes place in which base abstract hydrogen from OH group: