Regioselective Phenol or Carbinol Glycosidation of 17(beta)-Estradiol and Derivatives Thereof

Unprecedented regioselective glycosidations of 17b-estradiol and nitro substituted derivatives thereof either at the phenol or carbinol position is reported. In the former case, glycosyl bromides or iodides were employed as the donors in a base promoted reaction conducted under two-phase conditions. In the latter case, glycosyl trichloroacetimidate donors were used in combination with the mild activation of 4 A acid washed molecular sieves.