A facile synthesis of C2-symmetric 17β-estradiol dimers

A rapid and efficient synthesis of a series of C2-symmetric 17β-estradiol dimers is described. The new molecules are linked at position 17α of the steroid nucleus with either an alkyl chain or a polyethylene glycol chain. They are made from estrone in five chemical steps with an overall yield exceeding 30%. The biological activity of these compounds was evaluated in vitro on estrogen dependent and independent (ER+ and ER−) human breast tumor cell lines: MCF-7 and MDA-MB-231. Some of the dimers present selective cytotoxic activity against the ER+ cell line.