Chapter 26 - Carbonyls and Carboxylic compounds Flashcards
Define carbonyl compound
A compound containing the C=O functional group
Give 2 examples of a carbonyl compound
Aldehydes
Ketones
What is the suffix for an aldehyde?
-Al
What is the suffix for a ketone?
-One
Where is the C=O located in an aldehyde?
At the end of the chain
Where is the C=O located in a ketone
In the middle of a chain
What are carbonyls said to be in they contain a benzene ring?
Aromatic
What are carbonyls said to be if they do not contain a benzene ring?
Aliphatic
What is the simplest aromatic aldehyde called?
benzaldehyde
What is the simplest aromatic ketone called
Phenylethanone
What happens when a primary alcohol is oxidised under distillation?
It becomes an aldehyde
What happens when a primary alcohol is oxidised under reflux?
It becomes a carboxylic acid
What happens when a secondary alcohol is oxidised under reflux?
It becomes a ketone
What happens when a tertiary alcohol is oxidised under distillation or reflux?
Nothing as they are resistant to oxidation
What are alcohols reacted with to oxidise?
Acidified dichromate
Define reflux
The continual boiling and condensing of a reaction mixture to ensure that a reaction takes place without the contents of the flask boiling dry
What can an aldehyde be reduced to?
a primary alcohol
What can a ketone be reduced to?
a secondary alcohol
What is the reducing agent used for reduction of carbonyl compounds?
NaBH4
What are the conditions for the reduction of carbonyl compounds?
Warm and a H20 solvent
How can NaBH4 be represented in an equation showing the reduction of an alcohol?
[H]
How many [H] are required to reduce an aldehyde or a ketone to an alcohol?
2[H]
What is the mechanism used to reduce a carbonyl to an alcohol?
Nucleophilic addition
Why is it nucleophilic?
Because NaBH4 reacts with a carbonyl to produce an alcohol it releases a H- ion in solution, which is a nucleophile as it is attracted to positively charged areas
Define nucleophile
an atom or group of atoms which is attracted to an electron deficient centre, where it donates a pair of e- to form a new covalent bond
Define addition
a reaction in which a reactant is added to an unsaturated molecule to make a saturated molecule
What mechanisms are required to make a hydroxynitrile from a carbonyl?
nucleophilic addition
What reagent is used to make a hydroxynitrile?
HCN
What ions does the reagent used to make a hydroxynitrile have?
CN-
Which atom in a carbonyl will CN- be attracted to? Why?
C, because it is partially positive
Which bond breaks when CN- is attracted to C? What happens after that?
C=O breaks, C-O forms and C-CN forms and O-H forms
Explain the process of reduction of an alcohol by NaBH4?
The C=O bond in the carbonyl is polar, with the C being partially positive and the O being partially negative.
The hydride ion from NaBH4 is attracted to the C as it is a nucleophile, and forms a covalent bond with it using the lone pair.
One of the bonds in the C=O breaks and the pair of electrons goes to the O atom, so the O atom becomes negatively charged
The O atom uses the lone pair to form a bond with the H of a H20 (from the water solvent) and the OH bond in the water molecule breaks, forming an alcohol and an OH- ion.