Synthesis of highly pure dolichyl and cholesteryl esters.

Highly pure dolichyl and/or cholesteryl esters can be synthesised at room temperature by reacting a defined pure dolichol and/or pure cholesterol with an acyl chloride in the presence of pyridine. During the reaction some acyl anhydride originates as a secondary product. It can be hydrolysed by methanolic KOH and removed by a rapid percolation of the reaction mixture through a small alumina column. A final purification of the raw product obtained by silicic-acid/celite column chromatography makes it possible to obtain highly pure esters with a satisfactory yield.