Page 145 - Pharm.Org.Chem-I 02-06-05-101
P. 145
Exercise
Reaction Product/products Type of Type of solvent
Mechanism
n-propylchloride +
NaSH
Isobutyl iodide
+KOCH3
Tert.butyl bromide
+ H2O
Neopentyl
chloride + H2O
Allyl bromide +
H2O
Allyl bromide +
NaCN
Elimination reactions
Elimination reactions are competing with nucleophilic
substitution reactions when the nucleophile also
acts as a base.
α
β
Elimination or substitution? In general terms:
• strong bases favour elimination;
• large bases favour elimination;
• steric crowding in the alkyl halide favours elimination;
• high temperatures and aprotic polar solvents favour elimination.
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