[bhkuk]

i am making areaction with (-)Menthyl (R)-p-toluenesulfinate with methylmagnesium iodide, the reaction thake place at anhydrous benzene. after doing the reaction i am making hydrolyse with ammonium chloride.
 
after hydrolize of the product ,i should then evaporate my solvent (ether)
after evaporation i add hot hexane till watching white cloudy
i should cold it for the night at -5C and then filtrate it.
the crystals i get i should dissolve at minimum of hot ether and then adding hot n-hexane untill i will see again white cloud, i should cool it again to -5C and the n filtrate and pack the crystals
what happened in this process? why should i do this procedure?