Aldehydes and Ketones Flashcards
What are Aldehydes reduced to?
1° Alcohols
What are ketones reduced to?
2° alcohols
what is a nucleophile?
Electron pair donor
What mechanism reduces ions and ketones to alcohols?
nucleophilic addition
what is the reagent for nucleophilic addition alcohols?
NaBH4
aqueous solution
what is the equation for a nuclear for addition to form alcohols?
A/K + 2[H]> alcohol
what is hazardous about potassium cyanide (KCN)?
it is an irritant and toxic when eaten
When it reacts with water, it forms HCN, which is a highly toxic gas
when reducing aldehydes and ketones using KCN,how this be carried out to ensure safety
in a fume cupboard with goggles, gloves and a Lab coat
What does potassium cyanide (KCN) reduce aldehyde and ketones to?
Hydroxynitries
what is the overall equation for nucleophilic addition to form hydroxynitriles?
A/K + KCN + HCL > hydroxynitrile + KCL
What is an optical isomer (enantiomer) ?
same chemical and physical properties
contain a chiral centre
what is a chiral centre?
A single carbon atom is bonded to 4 different atoms/groups
what are the properties of an asymmetric carbon?
- no centre of symmetry
- no plane of symmetry
- no axis of symmetry
what is the one difference between enantiomers?
They rotate the plane of polarise light in opposite directions
what is a racemic mixture?
contains equal amounts of an enantiomer and is optically inactive
what happens if a sample is optically active?
enantiomers i’m not equal so a rotation of the light will be detached
what does that mean if a sample is optically inactive?
enantiomers are an equal amount and they rotate the plane of authorise light in opposite directions equally
why are some drugs optically active?
body may have a specific enzyme based receptor which will only accept a particular isomer
leadss to effective/effective drug isomers
How do you overcome the problem of optical active drugs?
- separate the two isomers (difficult because they have the same chemical properties)
- Sell the drug as a mixture so half of it is useless
- Only make the required isomer
what creates equal amount of enantiomers
the C=O bond in A/K is planar
so there is equal chance of the nucleophile attacking the delta positive carbon from above AND below the plane of the molecule
so enantiomers are formed in equal amounts
