MCAT Organic Chemistry Carbonyl Chemistry Flashcards
A reaction in which the enolate anion of the carbonyl reacts with the carbonyl of another compound
Aldol condensation
A reaction between an aldehyde or ketone and a primary amine to form an ___
imine
A functional group in which a carbonyl is attached to two carbon groups
Ketone
The hydrolysis of esters by treatment with a basic solution
Saponification
Readily interconvertible constitutional isomers
Tautomers
What is a typical electrophile involved in an SN2 mechanism?
An alkyl halide because:
- electronegative
- large in size
- Conjugate bases of strong acids (except F-) make good leaving groups
Why should protic solvents be avoided when doing SN2 reactions?
The hydrogen bonding solvents are able to strongly solvate the nucleophile, they hinder the backside attack necessary for the concerted reaction
Why should you use an aprotic solvent when running an SN2 reaction?
Polar aprotic solvents like Acetone, DMF, or DMSO are polar in nature allowing the charged nucleophiles and leaving groups to remain dissolved, but not as efficient at completely solvating the nucleophile
Reactivity of a substrate in order of best to worse for an SN2 reaction
Ch3 > Primary > Secondary > Tertiary (BECAUSE OF STERIC HINDRANCE)
Are rearrangements possible for SN2 mechanisms?
NO it is a concerted (one step) mechanism. No carbocations are present in solution
What are the favorable conditions of an SN2 mechanism?
Strong, non-bulky nucleophil will favor SN2 reaction over SN1
The rate of an SN1 rxn rate is dependent on __
concentration of the electrophile (species that loses the leaving group over the course of the reaction)
Because nucleophile attacks on either side, SN1 reactions involving chiral molecules will produce a __
racemic mixture of R and S
Reactivity of a substrate to SN1 reactions
Tertiary > Secondary > Primary (due to stabilization of the carbocation intermediate)
Why do SN1 reactions favor protic solvents?
Protic solvent helps to stabilize the forming carbocation and solvate the leaving group,
Second, the solvent behaves like a nucleophile in a solvolysis reaction attacking the carbocation intermediate producing an alcohol if water was used or an ether if an alcohol was used
What are the 5 Aqeuous oxidants that can be used to form ketons from secondary alcohols?
- Chromic acid (H2CrO4)
- Chromate salts (CrO42-)
- Dichromate Salts (Cr2O72-)
- Permanganate (MnO4-)
- Chromium Trioxide (CrO3)
The only anhydrous oxidant that will not overoxidize the primary alcohol to the carboxylic acid form, but into a ketone is __
PCC
The general structure of an amine is
R-NH2
Amines behave as either ___ or __
Bronsted-Lowry bases or nucleophiles
When an aldehyde or keton reacts with a primary amine (RNH2) a __ will form
An imine will form C=N-R’
When an aldehyde or keton reacts with a secondary aine (R2NH) a __ will form
An enamine will form C-N-R2
___ is a test to detect aldehydes, ketones, and hemiacetals in sugars
Benedict’s test
Formula for carbohydrates
CnH2nOn
The bond between two saccharides
Glycosidic linkage
Interconversion between anomers
Mutarotation