To a solution of dehydroepiandrosterone (2.88 g, 10 mmol) in THF (100 mL) is added sodium hydride (11 mmol, 60% in oil) at room temperature under an argon atmosphere. When all the sodium hydride has reacted, chloromethyl acetate (prepared from acetyl chloride and formaldehyde (or derivative) using ZnCl2 as catalyst) is added and the mixture is heated for a few hours. After cooling, the mixture is poured into water and extracted with ethyl acetate. The organic phase is then washed with water, dried, filtered and evaporated to dryness to give the desired compound.
