What does mCPBA do to alkene?
Oxidation Of Alkenes With mCPBA mCPBA forms epoxides when added to alkenes. One of the key features of this reaction is that the stereochemistry is always retained. That is, a cis alkene will give the cis-epoxide, and a trans alkene will give a trans epoxide. This is a prime example of a stereoselective reaction.
What does CH2Cl2 do to an epoxide?
In non-nucleophilic solvents (e.g., CH2Cl2), reaction stops at epoxide. Addition of 2 H’s is syn, because they replace C-Pt bonds at the catalyst surface. Adds two H atoms to the same face of an alkene (to yield an alkane).
What can be used instead of mCPBA?
Consequently, MCPBA is popular for laboratory use. However, MCPBA can be explosive under some conditions. Peroxycarboxylic acids are sometimes replaced in industrial applications by monoperphthalic acid, or the monoperoxyphthalate ion bound to magnesium, which gives magnesium monoperoxyphthalate (MMPP).
Is mCPBA a strong acid?
A white solid, it is used widely as an oxidant in organic synthesis. mCPBA is often preferred to other peroxy acids because of its relative ease of handling. mCPBA is a strong oxidizing agent that may cause fire upon contact with flammable material….meta-Chloroperoxybenzoic acid.
| Names | |
|---|---|
| GHS hazard statements | H226 , H314 , H318 , H335 |
How is epoxidation of alkenes done with mCPBA?
This is usually done with peroxyacids such as MCPBA ( meta -chloroperoxy benzoic acid) or Peroxyacetic acid: The mechanism of epoxidation is similar to the formation of halonium ion and oxymercuration that we discussed in the other addition reactions of alkenes.
Where does the cyclopropane reaction of an alkene take place?
CHCl3, KOH Cl Cl H H CH2I2, Zn(Cu) H H ether 6 The cyclopropanation reaction of an alkene with a carbene takes place in a single step. There is NO intermediate. As such, the geometry of the alkene is preserved in the product. Groups that are trans on the alkene will end up trans on the cyclopropane product.
How is the geometry of the alkene preserved in the epoxide product?
120 Stereochemistry of the mCPBA epoxidation: syn addition of oxygen. The geometry of the alkene is preserved in the product (recall the cyclopropanation of alkenes, Ch. 7.6) Groups that are trans on the alkene will end up trans on the epoxide product. Groups that are cis on the alkene will end up cis on the epoxide product.
How to predict the reaction of cis-2-hexene with mCPBA?
Predict the product of the reaction of cis-2-hexene with MCPBA (meta-chloroperoxybenzoic acid) a) in acetone solvent. b) in an aqueous medium with acid or base catalyst present. 2. Predict the product of the reaction of trans-2-pentene with magnesium monoperoxyphthalate (MMPP) in a chloroform solvent.
