aldehyde and ketone Flashcards
position of carbonyl group in aldehyde and ketone
in aldehyde the the carbonyl grp is at the terminal or end carbon and in ketone the carbonly grp is within the carbon chain.
typical representatives of aldehyde and ketone are which compounds? (4)
formaldehyde, acetone, benzaldehyde, acetophenone
use of formaldehyde, acetone, benzaldehyde,
formaldehyde in producing resins,plastics
acetone in iodoform chloroform and nail polish remover
benzaldehyde in dyes making
physical state of aldehyde and ketone
methanal ethanal are gases
lower ald and ketone are colorless liq
higher ald and ketone are solids
why boiling point of ald and ketone high than alkanes but lower than carboxylic and alcohols
more than alkanes bcs of polar nature
less than carboxyl and alcohol bcs of no intermolecular hydrogen bonding
structure of ald and ketone (structure of carbonly group)
the carbonly grp consist of carbon double bonded to oxygen. carbon atom is sp2
hybridized.
triganol geometry with 120 angle
carbon uses its 4 orbitals to make double bond w oxygen, and onamewith other atoms.
name only methods of prep of ald and ketones (OHOF)
1) ozonolysis of alkenes
2) hydration of alkynes
3)oxidation of alcohol
4)friedel craft acylation
what happens in ozolysis of alkene
how can we distinguish if the product will be aldehyde or ketone
ozone reacts with alkene to form ozonide which then forms 2 aldehydes or 2 ketones.
if the carbon of c=c double bond is attach to terminal carbon aldehyde will form
if carbon of c=c double bond is attach to carbon within chain so the ketone formed
what type of reaction is hydration of alkyne? and what acid and agent used
its an acid catalyzed addition reaction where sulphuric acid and catalyst mercuric sulphase
what happens in hydration of alkyne
how can we distinguish if the product will be aldehyde or ketone
alkyne react with water in presence of H2SO4 and HgSO4 to form enol which tautomerize to forms aldehyde or ketone.
if enol has OH at the end wala carbon, we get aldehyde
if enol has OH within carbon chain, we get ketone
oxidation of alcohol
prim alcohol oxidize to form aldehyde
sec alcohol oxidize to form ketone
what catalyst used in oxidation of alcohol
PCC pyridinium chlorochromate
friedel craft acylation what catalyst used
benzene reacts with acyl chloride to form aromatic ketone in presence of lewis catalyst ALCL3
reactivity in ald and ketone is bcs of ? distribution of charges in oxygen and carbon
bcs of polar nature of carbonyl group the oxygen has an partial negative charge (acts as nucleophile) and carbon has partial positive charge (acts as electrophile)
whos more reactive ald or ketone and why
aldehyde more reactive than ketone bcs of less hindrance due to attachment of one alkyl group
name only 3 types of reactions ald and ketones go through (NOR)
1)nucleophilic addition reaction
2)reduction
3) oxidation
what happens in nucleophilic addition reactions and type of n.a reactions
nucleophile attach carbonyl carbon
the carbon hybridization change from sp2 to sp3
alkoxide intermediate forms
2 TYPES
Acid catalyzed and base catalyzed
whats the common reason they occur?
main diff in mechanism of acid and base catalyzed nhile addition reactions
they occur bcs of weak n.phile
the main diff in mechanism is that acid catalyzed, the acid gives proton to the electrophile
in base catalyzed the base takes away proton of n.phile
when is acid catalyzed occur and tell mechanism
when there is a weak nucleophile
MECHANISM
acid attack and donate its H+ ion to the carbonyl group and make it more positive
this enhances the electrophilic nature of carbon
the weak n.phile can easily attack the e.phile and form alkoxide and then product
example of acid catalyzed n.phile addition reactions
addition of Hydrazine (NH2-NH2) and of hydroxyl amine (NH2-OH) in ald and ketone
when is base catalyzed occur and tell mechanism
when there is weak n.phile
MECHANISM
the base attack the nphile and takes away its proton (H+ ion)
and make it strong
this nphile attack carbon of carbonyl group
alkoxide intermediate forms
and then the producte
example of base catalyzed reactions
addition of HCN and Grignard reagent in ald or ketone
what happen in reduction of ald and ketone and what two types of prod formed and how 2 change prod forms
addition of hydrogen in carbonyl group of ald and ketone.
reduction of ald and ketone
FORMS ALKANES OR ALCOHOL
by changing the reduing agent we get 2 diff products
name only the 2 process of reduction to form HYDROCARBONS
1)clemmensen process
2)Wolf kishner process
