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Created by mitzigolsorkhi
about 9 years ago
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Question | Answer |
what is this? | aldehyde |
how is aldehyde characterised? | the carbonyl group is alway attached to a hydrogen and oxygen with a double bond |
what is this? | ketone |
how is ketone characterised? | has a double bond oxygen with two R functional groups |
when naming an aldehyde where do you start? | at the carbonyl (oxygen bonded carbon) and add al to end e.g. pentanal |
you calculate the steric number by? | no of sigma bonds + no of lone pairs of electrons |
ketone is more stable than aldehyde why? 2 reasons | 1. R group is electron donating, and ketone has 2, therefore able to balance the electron pull that oxygen has better. Aldehydes are therefore more positive at the carbon and therefore attract a neutrophile better 2. ketones steric hindrance - the R groups get in the way of reactions. |
the a hydrogen is the hydrogen attached where? and where is the B-carbon? | a- hydrogen is attached to the carbon next to the carbonyl group B- carbon is the carbon adjacent to the to a-carbon |
the a-hydrogen may be removed by what? | a base |
the acidity of this hydrogen is increased how? | if it is between 2 carbonyl groups |
which hydrogens are the only ones that are acidic? | a-hydrogens |
enol = | alkene + alcohol |
the O of the carbonyl forms hydrogen bonds with what? | the hydrogens attached to other electronegative atoms such as N or O Since there are no hydrogens attached to the carbonyl O - aldehydes and ketones do not form hydrogen bonding with themselves (instead they do dipole -dipole bonding) |
aldehydes will be oxidised to what? | carboxylic acids |
do ketones oxidise? | rarely |
primary alcohols can be oxidised to yield what? | aldehydes |
secondary alcohols can be oxidised to yield what? | ketones |
alkenes can be oxidatively cleaved to yield what? | ketones and aldehydes when treated with Ozone O3 (ketones can only be made if the double bond of the alkene carbon atoms is di-substituted) |
what does vinyl mean? | In chemistry, vinyl or ethenyl[1] is the functional group −CH=CH2, namely the ethylene molecule (H2C=CH2) minus one hydrogen atom. |
hydration of terminal alkynes will yield whAT? | methyl ketones |
a nucleophile attack to an aldehyde or ketone results in what? | a tetrahedral alkoxide ion intermediate is formed which can lead to the formation of an alcohol OR expel the carbonyl oxgyen atom as H20 or OH- to form a carbon-nucleophile bond |
aldehydes and ketones react with water in the presence of acid or base catalyst to form what? | 1,1 -diols water acts as a nucleophile attacking the carbonyl carbon |
reduction of aldehydes and ketones yields what? grignard reagents react with the following to form what? 1. formaldehyde 2. aldehyde 3. ketone | alcohol 1. primary 2. seondary 3. tertiary |
what are NaBH4 and LiAlH4? | reducing agents |
what is this? | formaldehyde |
imines and examines are formed when aldehydes and ketones react with what? | amines |
when an aldehyde or ketone reacts with a primary amine what is formed? | an imine (or schiff base) |
what is the general formula of a primary amine? | R-NH2 (R = Alkyl or aryl group) |
in an amine the carbonyl group is replaced with what? | C=N-R |
When an aldehyde or ketone reacts with a secondary amine, what is formed? | enamine |
a secondary amine has what general formula? | R2N-H |
what do aldehydes and ketones produce when they react with tertiary amines? R3N | They do not react! |
when dissolved in an excess of primary alcohol what will aldehyde and ketone form? | hemiacetal and hemiketals then they will make acetal and ketal if there is enough of the catalyst. |
hemiketal | |
hemiacetal | |
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