Chapter 13 Flashcards
(39 cards)
Reagents for deprotonating alcohols - to produce H2 gas
strong base
Reagents for deprotonating alcohols - to produce alkoxide ion
Li or
Na or
K
Factors affecting acidity of alcohols
resonance
induction
solvation effect
Factors affecting acidity of alcohols - resonance
resonance structures makes it more acidic
Factors affecting acidity of alcohols - induction
electron withdrawing of electronegative atoms increases stability, making more acidic
Factors affecting acidity of alcohols - solvation effects
sterically hindered solutions arent stabilised, so less acidic
Preparation of alcohols
made by substitution reactions
Preparation of alcohols - primary substrate
NaOH
Preparation of alcohols - tertiary substrates
H2O
Preparation of alcohols - secondary substrates
neither SN1 or SN2 is effective
Alcohol preparation from alkene - acid catalysed - reagents
dilute H2SO4
Alcohol preparation from alkene - acid catalysed
most substituted
Alcohol preparation from alkene - oxymercuration demurcation - reagents
Hg(OAc)
H2O
NaBH4
Alcohol preparation from alkene - oxymercuration demurcation
most substituted
Alcohol preparation from alkene - hydroboration - reagents
BH3.THF
H2O2 NaOH
Alcohol preparation from alkene - hydroboration
less substituted
Preparation of alcohols via reduction
decreases oxidation state
reduces ketone or aldehyde to alcohol
Preparation of alcohols via reduction - reagent 1
H2
Pt,Pd or Ni
Preparation of alcohols via reduction - reagent 2
NaBH4
H2O, MeOH or EtOH
Preparation of alcohols via reduction - reagent 3
1) LAH
2) H2O
NaBH4 and LAH - double bonds
will not reduce the double bond
LAH
will react with an ester or COOH to produce alcohol
Diols preparation
prepared by excess reduction reagents or dihydroxylation of alkene
Dihydroxylation of alkene - syn- reagents
OsO4
NMO