Stereoselective synthesis of selenosteroids

A stereoselective synthesis of selenosteroids 4 and 5 has been achieved. Starting from commercial available cholesterol 1, followed by asymmetric epoxidation, and subsequently, by stereoselective epoxide ring opening, employing a selenium nucleophilic species, the correspondent products were afforded in high yields. The compounds were being evaluated for their biological activity and as a chiral pool for asymmetric transformations.