ALCOHOLS Flashcards
what are alcohols
compounds with OH group (hydroxyl)
when naming alcohols, what is the same consistent first step
choosing the parent, identify the longest chain that includes the carbon connected to the -OH group
what is the alcohol suffix
-ol
what is phenol
It has an -OH group attached directly to a phenyl ring.
what can a phenol be used to identify specifically
A phenol can specifically be used to identify hydroxybenzene
what is the boiling point of alcohol compared to other hydrocarbons
higher compared to alkane counterparts
why is the boiling point of alcohols higher than its alkane counterparts
they have O-H bonding
how can the acidity of a compound be determined
look at stability of conjugate base - more stable conjugate base the great the acidity
what are alcohols more acidic than
alkanes
why are alcohols more acidic than alkanes
the negative charge on the oxygen is more stable than the negative charge on a carbon
what is the conjugate base of alcohol called
alkoxide ion [neg charge]
R – O-
what two factors affect the acidity of an alcohol [when selecting between structures]
Resonance
Induction
how does resonance affect the acidity of an alcohol
if resonance present > acidity is greater
how does induction affect acidity of an alcohol
the more electronegative atoms in the alcohol - the more acidic it is
what is the property of electronegative atoms
they can attract a negative charge toward them so conjugate base is stabilise
electron-withdrawing substituent can increase acidity of nearby atom aka alcohol
list the electronegative atoms that would make alcohol most acidic from most electronegative to least electronegative in an alcohol
F
Cl
Br
I
in induction/electronegativity, what conditions are more likely to make an alcohol more or less acidic
distance between the electronegative element and the negative charge on the O in the conjugate base
what is a Grignard reagent
alkyl halide + magnesium
R-Mg-X
Why is a C-MG bond so significant
Carbon and magnesium have such a great difference in electronegativity that the bond between them can be treated as separate charges
how does the Grignard reagent act
as a nucleophile
how does the carbon nucleophile act
it can attack range of electrophiles including carbonyl group of ketones and aldehydes [C=O]
what happens if the Grignard reaction attacks the carbonyl group of a compound
- Gringard reagent acts as nucleophile and attacks carbonyl group
- Causes proton to be transferred from R-Mg-X to alkoxide ion on compounds
- Forms an alcohol
