Reactions and Conditions Flashcards
haloalkanes have 2 main reactions which are…
elimination and substitution
elimination eqn is?
eqn, reagent and condition
haloalkane => alkene + HX
reagent : KOH/NaOH, alcohol, reflux
name : dehydrohalogenation
eqn for preparation of haloalkane from alkane and alkene respectively
CH3CH3 => CH3CH2Br
condition : Br2, CH2Cl2, UV
CH2=CH2 => CH3CH2Br
condition : HBr (use markovnikov rule)
haloalkane has 7 nucleophilic substitution reactions…
- WITH H2O (FORM ALCOHOL + HX)
- WITH NAOH(aq) (FORM ALCOHOL + NAX)
- WITH EXCESS NH3 (FORM RNH2 + HX)
- WITH KCN, ETHANOL, REFLUX (FORM RCN ETHER + KX)
- WITH ROOK, ETHANOL (ANY SALT) (FORM ESTER + HX)
- WITH ROK (FORM ESTER + KX)
- WITH ALCOHOL (FORM ETHER + HX)
1’ HALOALKANE UNDERGO SN1 OR SN2?
SN2. ONLY IF STRAIGHT CHAIN.
3’ HALOALKANE UNDERGO SN1 OR SN2?
SN1
1’ HALOALKANE WITH BULKY ALKYL GRP WILL UNDERGO SN1 OR SN2?
SN1
SN2 HYDROLYSIS OF 1’ HALOALKANE IS SLOWER FOR THE ONE WHICH HAS BULKY ALKYL GRP. WHY?
- COZ THE PRESENSE OF BULKY ALKYL GRP WILL SHIELD THE NUCLEOPHILE FROM BACK-SIDE ATTACK.
- THUS IT WILL UNDERGO SN1.
EQN OF PREPARATION OF GRIGNARD REAGENT
CH3CH2Br + Mg =>
CH3CH2-Mg-Br
REAGENT : DRY ETHER
HYDROLYSIS OF GRIGNARD REAGENT FORMS?
ALKANE
EQN FOR HYDROLYSIS OF GRIGNARD REAGENT?
CH3CH2-Mg-Br => CH3CH3
ON ARROW : H30+
GRIGNARD REAGENT WITH METHANAL (CH2O) FORMS?
CH3CH2-Mg-Br + CH2O => 1’ ALCOHOL
ON ARROW : DRY ETHER, H30+
GRIGNARD REAGENT WITH ALDEHYDE (CH3CHO) FORMS?
CH3CH2-Mg-Br + CH3CHO => 2’ ALCOHOL
ON ARROW : DRY ETHER, H30+
GRIGNARD REAGENT WITH KETONE (CH3CHOCH3) FORMS?
CH3CH2-Mg-Br + CH3CHOCH3 => 3’ ALCOHOL
ON ARROW : DRY ETHER, H30+
GRIGNARD REAGENT WITH CO2, H30+ FORMS?
CH3CH2-Mg-Br => CA
ON ARROW : CO2, H30+
