Oxygen Containing Reactions Flashcards
What are the good SN2 leaving groups to know for the MCAT?
water I-, Br-, Cl- Acetate Tosylate ion (-OTs) Mesylate ion (-OMs)
What type of solvent does SN2 favour?
polar aprotic
What are 6 common polar aprotic solvents to remember for the MCAT?
acetone ether DMSO DMF THF HMPA
Which reaction yields a racemic mixture?
a) SN1
b) SN2
a) SN1
What is first order kinetics?
rate of the reaction depends only on the concentration of the substrate but occurs over 2 steps
rate = k[substrate]
Which reaction shows first order kinetics?
a) SN1
b) SN2
a) SN1
Does the nucleophile affect the rate of SN1 reactions? Explain.
NO –> nucleophilic attack occurs after the rate-limiting step (carbocation formation)
What type of solvent favours SN1 reactions?
polar protic solvents
Give an example of a polar protic solvent.
NaOH
anything that can form hydrogen bonds
Determining structure of a given molecule
what reagents and solvents are needed for the preparation of alkyl halides from a tertiary alcohol
HCl, HBr and HI - reagents
diethyl ether - solvent
is the preparation of alkyl halides from an alcohol a Sn1 or Sn2 reaction
Sn1
what is the general reaction of an ether in the presence of a strong acid
ether + strong acid => alkyl halide + alcohol
what are the seven carbonyl compounds
aldehyde, ketone, carboxylic acid, acyl chloride, anhydride, ester and amide
true or false - aldehydes and ketones undergo nucleophilic addition
true
true or false - a primary alcohol can be oxidized into a aldehyde but not a carboxylic acid
false - it can be oxidized into both
what is the reagent used to oxidize a primary alcohol into a aldehyde
PCC
what reagent is needed to oxidize a aldehyde into a carboxylic acid
Tollen’s reagent - Ag(NH3)2
what reagent is used to oxidize a primary alcohol straight into a carboxylic acid
KMnO4, Jones reagent and H2CrO4
what does a secondary alcohol oxidize into
a ketone
true or false - tertiary alcohols undergo oxidation
false - they do not
what reagents are needed to reduce an aldehyde and ketone and what are the products
sodium borohydride and ethanol followed by an acid workup - the products are primary and secondary alcohols
what reagents are needed to reduce a carboxylic acid and ester to a primary alcohol
lithium aluminum hydride/diethylether, followed by an acid workup
what is the product of a reaction between an aldehyde/ketone and an alcohol
hemiacetal
true or false - alpha hydrogens to a carbonyl are basic
false - they are acidic
what are the two ways an enolate anion can accept a proton
- accepts a proton in its carbanion forming a ketone
2. accepts a proton forming an enol
how does enolates react
through base catalyzed alpha substitution
