Double Peroxidation Lab Report

Lab #2 (Part A,B)

Due date: Oct 5, 2010

1 - Theory and mechanism

Epoxidation is a reaction of an alkene with a peroxycarboxylic acid (also called peracid) to produce an epoxide product, generally performed in inert solvents, such as dichloromethane. The epoxide product is a cyclic ether in which the ring contains three atoms. The alkene gains an oxygen from the peracid in a syn fashion. In this experiment, R-(－)-carvone is reacting with MCPBA, a peracid, to produce the epoxide product.
Balanced equation:

C10H14O + C7H5ClO3 --> C10H14O2 + C7H5ClO2

Since the rate of reaction depends on the electronic density of the double bond, and R-(－)-carvone has two double bonds, the reaction is regioselective. The more electron-riched double
In this experiment it is used to visually identify the production in the previous reaction, since it changes color from purple to yellow-brown if reacted with alkene under aqueous conditions.
Balanced equation:

C10H14O2 + KMnO4 + 2H2O --> C10H16O4
Mechanism:

2 - Table of reagents .
|Compound |Mol Mass (g/mol) |
|Dissolution of MCPBA in CH2Cl2 |solution was clear, MCPBA dissolved |
|Dissolution of R-(－)-carvone in the solution |solution stayed clear |
|1.5 h after reaction |solution was cloudy white |

Part B: Syn dihydroxylation and visualization using KMnO4 (on a TLC plate)
|Important steps |Observations |
|TLC after 15 min, dipped in KMnO4 solution |All spots turned yellow-brown
|TLC after 1 h, dipped in KMnO4 solution |All spots turned yellow-brown |
|TLC after 1.5 h, dipped in KMnO4 solution |The starting material was almost consumed;