Synthesis of 3,3,5,5-Tetramethylcyclohexanone

Synthesis of 3,3,5,5-tetramethylcyclohexane with Gringard reagent.

Introduction:

Genral reaction:

Figure 1: Genreal reaction

"The Grignard reagents are prepared by the action of activated magnesium (Rieke magnesium) on organic halides in suitable solvents like Diethyl ether, Et2O or Tetrahydrofuran, THF in anhydrous conditions"[1].  An imposrtant advantage of alkyl halide reaction with gringnard reagents is that the sequence can be used to introduce deuteruim into a soecific site in a molecule as can be seen in rhis reaction in figure 2 is achieved by the gringard reagent in arganometalic reactions (gillman type reagents). The gignard reagent is treated with deuterated acid.

[1]

Figure 2

Figure 3

As seen in the figure abovoe the starting material of all regents in Grignard reaction must not have any acidic protons (nucleophilic and strong basis) otherwiseit would not be possible to create a grignard reagents.

Thurther ethanol is often present in the teccniacal grade of diethyl ether but if the technical grade was used it would react with the ethanol . Grignard reagents are very basic and react readily with water or any compound containing a hydroxy group and therefore anyldrous diethyl ether must be used instead. For example:

Acetic acid was also needed in this reaction to form Mg-alkoxide.

Mg-alkoxide.

Acetic acid

Figure;4: Acetic acid and Mg-alkoxide.

In this experiment there was only 0.08 mol of 3,5,5 -trimethylcyclohex-2-enone that reacted with methylcopper when only about 0.03 mol of cuprous ion was added to the methylmagnesuim iodide this was possible because in the methylmagnesuim iodide the magnesuim metal

Figure 5: Ch3MgI. 2(C2H5)2O

In the figure above a a pluasabile 3D structure is givenfor the complex of Ch3MgI. 2(C2H5)2O

"Reactions of organocopper reagents involve species containing copper-carbon bonds acting as nucleophiles in the presence of organic electrophiles. Organocopper reagents are now commonly used in organic...