The Jones Reaction: the Oxidation of Borneol to Camphor Essay Example
Introduction
Reduction/Oxidation (Redox) reactions are ones that change the oxidation state of a compound. The oxidation state refers to the acquired charge (gained or lost electrons) of an element in relation to its original charge (i.e. S + 2e- S2+); in a compound, the overall oxidation state is calculated by adding all the charges of the elements present. The addition of electrons makes the element “reduced” and the loss of electrons is called “oxidized”. These reactions can be carried out in lab, or they can occur naturally via oxidants or reductants—substances that have the ability to oxidize or reduce other substances, respectively.
Theory, Reactions, and Mechanisms
In this lab, Borneol will be oxidized to camphor in a common reaction known as the Jones Oxidation Reaction. It is true that oxidation reactions subtract electrons, lowering its oxidation state. However in organic chemistry, a more detailed explanation of the oxidation reaction is appropriate for a better understanding; organic oxidation reactions are ones in which:
1. Oxygen is inserted into a bond
2. Hydrogen is lost across a bond
3. Carbon or hydrogen is replaced by a more electronegative element
There are several general reactions, and several reagents that catalyze the reaction according to the functional group it works on. For primary alcohols, several reagents can be used:
• The Jones reagent (CrO3/H+, Cr2O72-/H+, H2CrO4),
• Potassium permanganate (KMnO4/-OH or H+),
• Collins reagent (CrO2/Pyridine “PCC” (no water present)
Secondary alcohols use the same reagents as primary alcohols.
Tertiary alcohols are resistant to oxidation.
For the aldehydes, the Tollins reagent (Ag(NH3)2 is used in addition to the potassium permanganate and the Jones reagent.
Scheme:
Reagent Table and Instruments
Common Name Molecular Formula Molecular Weight (g/mol) Important Properties
Borneol C10H18O 154.25 Easily oxidized to the ketone that yields camphor;
Reduction/Oxidation (Redox) reactions are ones that change the oxidation state of a compound. The oxidation state refers to the acquired charge (gained or lost electrons) of an element in relation to its original charge (i.e. S + 2e- S2+); in a compound, the overall oxidation state is calculated by adding all the charges of the elements present. The addition of electrons makes the element “reduced” and the loss of electrons is called “oxidized”. These reactions can be carried out in lab, or they can occur naturally via oxidants or reductants—substances that have the ability to oxidize or reduce other substances, respectively.
Theory, Reactions, and Mechanisms
In this lab, Borneol will be oxidized to camphor in a common reaction known as the Jones Oxidation Reaction. It is true that oxidation reactions subtract electrons, lowering its oxidation state. However in organic chemistry, a more detailed explanation of the oxidation reaction is appropriate for a better understanding; organic oxidation reactions are ones in which:
1. Oxygen is inserted into a bond
2. Hydrogen is lost across a bond
3. Carbon or hydrogen is replaced by a more electronegative element
There are several general reactions, and several reagents that catalyze the reaction according to the functional group it works on. For primary alcohols, several reagents can be used:
• The Jones reagent (CrO3/H+, Cr2O72-/H+, H2CrO4),
• Potassium permanganate (KMnO4/-OH or H+),
• Collins reagent (CrO2/Pyridine “PCC” (no water present)
Secondary alcohols use the same reagents as primary alcohols.
Tertiary alcohols are resistant to oxidation.
For the aldehydes, the Tollins reagent (Ag(NH3)2 is used in addition to the potassium permanganate and the Jones reagent.
Scheme:
Reagent Table and Instruments
Common Name Molecular Formula Molecular Weight (g/mol) Important Properties
Borneol C10H18O 154.25 Easily oxidized to the ketone that yields camphor;