Chemistry 331 - Fall 1996

Chapter 7 - Alkyl Halides

New Skills

Knowledge - Level 1


know (or review) the terminology:

nucleophile
nucleophilic substitution
SN1, SN2, E1, E2
leaving group
inversion of stereochemistry
unimolecular / bimolecular
first-order / second-order kinetics
rate-determining step
steric effects
anti periplanar
Grignard reagent



Concepts - Level 2


understand the steps of the halogenation chain reaction:

initiation, propagation, termination

understand why the rate-determining step controls the overall rate of a reaction

understand the implications of a mechanism on the rate law for the reaction

unimolecular rate-determining step will show first-order kinetics
bimolecular rate-determining step will show second-order kinetics

understand the implications of a mechanism on the stereochemistry of the reaction

recognize the key features of the SN2 mechanism:

concerted backside attack of nucleophile

recognize the key features of the SN1 mechanism:

two-steps - rate-determining ionization, then reaction with nucleophile

recognize the key features of the E2 mechanism:

concerted anti periplanar elimination of H and X

recognize the key features of the E1 mechanism:

two-steps - rate-determining ionization, then loss of H+

recognize that substitution and elimination are often competitive reactions



Applications - Level 3


identify various nucleophiles

use various addition reactions of alkenes to prepare alkyl halides

use various substitution reactions of alcohols to prepare alkyl halides

show how to prepare Grignard reagents from alkyl halides

use Grignard reagents to convert alkyl halides to alkanes

predict products of nucleophilic substitution reactions on alkyl halides, including stereochemistry

predict elimination products from alkyl halides, including stereochemistry and the application of the Zaitsev Rule



Analytical Skills - Level 4 & higher


predict the preferred reaction mechanism(s) for a given alkyl halide under specified conditions: SN2, SN1, E2, E1

predict the best conditions to carry out a nucleophilic substitution reaction on a given alkyl halide

predict the best conditions to carry out an elimination reaction on a given alkyl halide

use substitution and elimination reactions in synthesizing given target molecules