Aldehydes & Ketones Flashcards
A ketone has ______ alkyl group(s) bonded to the carbonyl
Two
An aldehyde has ______ alkyl group(s) bonded to the carbonyl
One.
What is bound to the carbonyl of an aldehyde
An alkyl group and a hydrogen
If an aldehyde is attached to a ring the suffix _________ is used
Carbaldehyde
Ketones are named by replacing -e with the suffix_______
-one
What takes priority in naming, Carboxylic acids or Ketones?
Carboxylic acids
What prefix do you use when a ketone is a substituent?
-oxo or -keto
Do ketones and aldehydes act as electrophiles or nucleophiles? Why?
Electrophiles because the carbonyl carbon is partially positive due to the double bond between the oxygen and carbon pulling electrons away from carbon
Why is the dipole of carbonyl stronger than that in an alcohol?
The double bond in carbonyl is more electron withdrawing than the single bond between oxygen and hydrogen in alcohols.
Why are aldehydes more reactive to nucleophiles than ketones?
Less steric hinderance and less electron donating from alkyl groups
How can an aldehyde be produced from an alcohol
partial oxidation of a primary alcohol using PCC
How can a ketone be obtained from an alcohol?
From oxidation of a secondary alcohol with reagents including potassium or sodium dichromate salts and Chromium Trioxide
Why is the carbonyl carbon good for a nucleophilic attack?
It has a partial positive charge due to the electron withdrawing, Oxygen pulls electrons from carbon.
What type of bond forms as a result of a nucleophile attacking a electrophile?
A covalent bond is formed between the carbonyl carbon and nucleophile, breaking the double bond in the carbonyl
Breaking the pi bond of a carbonyl forms what type of molecular geometry intermediate?
Tetrahedral
If no good leaving group is present when a nucleophile attacks a ketone or aldehyde what forms?
An alcohol, the oxygen accepts a proton
If a good leaving group is present when a nucleophile attacks what happen?
Carbonyl reforms pushing off the leaving group
What is the result of a nucleophilic addition to a ketone or aldehyde?
An alcohol, no good leaving group available to leave so carbonyl does not reform
What is the result of a nucleophilic attack on a carboxylic acid?
Reformation of a carbonyl pushing off the LG
A nucleophilic addition to a ketone or aldehyde results int what type of molecule
an alcohol, with the nucleophile attached
In the presence of water aldehydes and ketones react to form
geminal diols
What is the result of a ketone or aldehyde nucleophilic addition in the presence of water
a geminal diol
Nucleophilic addition of an aldehyde or ketone with an alcohol results in
a hemiacetal or hemiketal
When two equivalents of alcohol with an anhydrous acid are added to ketones and aldehydes what is formed as a result?
Ketal and acetal by a nucleophilic substitution reaction
SN1 reactions are also known as nucleophilic _____ reactions because______
Substitution, the Nucleophile comes in THEN the leaving group leaves
How is an acetal formed from a hemiacetal?
Addition of another alcohol in the presence of an anhydrous acid that
What is the benefit of protonating a hydroxyl group of an alcohol and making it into water?
It makes it a better leaving group
Protonating alcohol forms a water which is a good leaving group
LG’s are more stable with an extra set of electrons
What forms when a ketone or aldehyde reacts with ammonium (NH3+)
Imine
Do nitrogens and nitrogen containing groups act as nucleophiles or electrophiles? Why?
Nucleophiles, because the lone pair of electrons on nitrogen
When ammonia adds to the carbonyl carbon what molecule is lost?
a water molecule
Cyanohydrins are formed by reacting what molecules?
Hydrogen Cyanide and ketones or aldehydes
