Aldols

Question 1

Answer 1

Base Catalyzed aldol condensation

Question 2

Carrying out what helps to ensure the formation of the intended product in cross-aldol condensations involving a ketone and an aldehyde?

Answer 2

using bulky base such as LDA will strongly favor removing hydrogens from the alpha-carbon that is the least sterically hindered. This favors the intended product instead of a mixture. With a non-bulky base, we cannot control which alpha carbons will have their hydrogens removed.

Question 3

Reaction is which two molecules of either ketones or aldehydes condense via nucleophillic attack

Answer 3

Aldol condensation

Question 4

What are the basic components of a robinson annulation?

Answer 4

Michael addition followed by aldol condensation

Question 5

What is the industrial relavence of robinson annulation?

Answer 5

It can help make steroid hormones

Question 6

What is the following reaction called?

Answer 6

Michael addition

Question 7

What are the basic components of a michael addition reaction?

Answer 7

An enolate attacks a beta carbon on an alpha beta destaurated ketone.

Question 9

How does the acid catalyst increase the rate of reaction in the following?

Answer 9

It increases the electrophilicity of the carbonyl carbon.

As evident from an early step in the reaction mechanism, an H+ ion protonates the carbonyl oxygen. This protonation makes the carbon-oxygen double bond significantly weaker, allowing the carbonyl carbon to become even more electrophilic (or partially positive) than before. This facilitates the reaction by increasing the chance that the nucleophilic enol will attack.

Question 10

What is the product of a michael addition?

Answer 10

1,5 dicarbonyl

Question 11

What tends to be the products of a robinson annulation?

Answer 11

Alpha beta unsaturated ketone, a six ememebred ring