Overview of some reactions used in this module

This module focuses on reaction schemes involving alkenes, alkanes, alcohols, and haloalkanes. Some of the exercises involving placing the reagents in schemes; others involving positioning of the compounds and some involve positioning of both reagents and compounds. The particular reactions and reagents are summarised below.

Interconversion of alkenes and haloalkanes by addition and elimination reactions.

CH₃CH=CHCH₃

KOH

Note that the conditions are not specified for use of either HX or KOH.
The focus is on the fact that one needs a base to eliminate HX from a haloalkane.

Interconversion of alcohols and haloalkanes by substitution reactions:

HX (substitution)

KOH (substitution)

HX in aqueous solution would be satisfactory for conversion of the alcohols in this module to halides.
H₂O is also formed in this reaction.

SOCl₂ is an another reagent that is commonly used to convert alcohols to chlorides.

Oxidation reactions of alcohols; reduction reactions of aldehydes and ketones

K₂Cr₂O₇/H⁺ (oxidation)

NaBH₄ or LiAlH₄ then H₃O⁺ (reduction)

In oxidation reactions the number of bonds AT CARBON to a more electronegative element (O in this case) are increased.

In reduction reactions the number of bonds AT CARBON to a less electronegative element (H in this case) are increased.

Reduction reactions of alkenes

CH₃CH=CHCH₃

H₂/Pd

(reduction)

CH₃CH₂CH₂CH₃

This is a reduction because a π (pi) bond between carbons has been replaced by TWO bonds from carbon to a less electronegative element.

Oxidation reactions of alkenes

CH₃CH=CHCH₃

KMnO₄ (oxidation)

This is an oxidation because a π (pi) bond between carbons has been replaced by TWO bonds to a more electronegative element.