Alpha Carbon Chemistry: Enols & Enolates cont

Question 1

When performing a claisen condensation reaction the starting ester must have _________

Answer 1

Have 2 alpha protons

Question 2

If another type of ester base was used instead of the group on the ester then a ____________ reaction will occurs & convert the present group on the ester to a different group

Answer 2

Transesterification

Question 3

Cross Claisen condensations

Answer 3

Are claisen condensation reactions that occur between two different partners

Question 4

What are the two criteria need for a claisen condensation reaction to occur?

Answer 4

1. If one ester has no alpha protons & can’t form an enolate
2. A direct claisen condensation can be performed in which LDA is used as a base to irreversibly form an ester enolate, which is then treated with a different ester

Question 5

Dieckmann cylcization

Answer 5

When claisen condensation undergo an intramolecular reaction where the product is a cyclic beta keto ester

Question 6

Intramolecular claisen condensation show a preference for formation of a ____ or ___ member ring due to ring strain

Answer 6

5 or 6

Question 7

The aloha position of a ketone can be alkylated by what two steps?

Answer 7

1. Formation of an enolate
2. Treating the enolate with an alkyl halide

Question 8

For alkylation reaction ______ is the base used

Answer 8

LDA

Question 9

The malonic ester synthesis

Answer 9

Is a technique that enables the transformation of halide into carboxylic acid with an introduction of two new carbon atoms

Question 10

The reagent used in a malonic ester synthesis is ____________

Answer 10

Diethyl malonate

Question 11

The 1st step in malonic ester synthesis is the ___________ of diethyl malonate

Answer 11

Deprotonation

Question 12

After the 1st step in a malonic ester synthesis what happens?

Answer 12

Then the enolate is treated with an alkyl halide resulting in an alkylation step

Question 13

Treatment with ________ results in the hydrolysis of both ester groups

Answer 13

aqueous acid

Question 14

If hydrolysis is performed at high temp then decarboxylation occurs to produce a ____________ where the enol then undergo tautomerization

Answer 14

monosubstituted acid & carbon dioxide

Question 15

Acetoacetic ester synthesis

Answer 15

Is a technique used to convert an alkyl halide into a methyl ketone introducing 3 new carbons

Question 16

What reagent is used for an acetoacetic ester synthesis

Answer 16

The reagent used is ethyl acetoacetate

Question 17

An alpha beta-unsaturated aldehyde or ketone has _____ electrophilic positions one at the beta position & other is the carbon of the carbonyl group

Answer 17

Two

Question 18

Both electrophilic positions can be attack by a __________

Answer 18

Nucleophile

Question 19

Grignard reagent tends to attack the ______ rather than the beta position

Answer 19

Carboynl group

Question 20

Micheal reaction

Answer 20

When the starting diketone is deprotonated to form a doubly stabilized enolate ion which then serves as a nucleophile in a 1,4-conjugate addition

Question 21

The doubly stabilize anolate is called a _______ & the alpha beta- unsaturated aldehyde is called a __________

Answer 21

Micheal donor, micheal acceptor

Question 22

Only doubly stabilize enolates can be a ___________ not regular enolate

Answer 22

Micheal donor

Question 23

A ketone can be converted into an _______ when treated with a secondary anime

Answer 23

Enamine

Question 24

An enamine can function as a _________ to undergo a Michael reaction

Answer 24

Micheal donor

Question 25

When treated with aquoues acid both NR₂ & enolate are converted into _______

Answer 25

carbonyl groups

Question 26

Stork enamine synthesis

Answer 26

Convers a ketone into an enamine to undergo a Micheal reaction & hydrolysis

Question 27

Robinson annulation

Answer 27

Two step reaction where a Michael reaction is followed by an intramolecular aldol condensation reaction to make a polycyclic compound

Question 28

The aldol addition, Claisen condensation, & stork enamine produce ___________

Answer 28

Difunctional compounds

Question 29

Aldol addition & Claisen produce ________ & stork produce 1,5 difunctional compounds

Answer 29

1,3 difunctionals

Question 30

In a micheal reaction the enolate can be treated with ______ to give the product

Answer 30

water

Question 31

In a Micheal rection the enolate can also be treated with an _______ which results in alkylation in the alpha position

Answer 31

an alkyl halide

Question 32

When adding the alkyl group they cant be the ______

Answer 32

Same