Quiz - Enols and Enolates | Enols and Enolates – Part 2

1

What is the product of the acid catalyzed reaction between Br2 and propanone?

1-bromopropan-2-one

Bromomethane and acetic acid

1,3-dibromopropanone

Propionyl bromide

2

Which organometallic reagent always results in an 1,4-addition?

RLi

RMgBr

R2CuLi

All of the above

Organolithium reagents (RLi): 1,2-addition
Gilman reagents (R2CuLi): 1,4-addition
Grignard reagents (RMgBr): 1,2 or 1,4-addition depending on reagent and substrate structure

3

Which of the following statements is incorrect about an enolate ion?

An enolate can be formed by deprotonation using NaOH

An enolate is a good electrophile

Enolate ion plays a role in Michael addition

An enolate is the conjugate base of an enol

An enolate is a good nucleophile

4

What are the different steps of a Robinson annulation?

1,2-Addition, Intramolecular aldol condensation

Enolization, Aldol dehydration

Michael addition, Intermolecular aldol condensation

Michael addition, Intramolecular aldol condensation, Aldol dehydration

5

What are the 2 functional groups produced during a Michael addition?

2 alcohols

2 carbonyls

1 carbonyl + 1 alcohol

1 carbonyl + 1 alkene

Michael addition:

6

Which statement is correct about the reaction between a Grignard reagent and an α,β-unsaturated carbonyl?

The reaction is selective (1,2- OR 1,4-addition) but depends on the structure of the reagent and the substrate

The reaction is not selective: products from a 1,2-addition AND from 1,4-addition are formed

The reaction is really slow compared to RLi and R2CuLi

The reaction is selective and results in an 1,2-addition

Organolithium reagents (RLi): 1,2-addition
Gilman reagents (R2CuLi): 1,4-addition
Grignard reagents (RMgBr): 1,2 or 1,4-addition depending on reagent and substrate structure