Stereoselective synthesis of bis-steroidal pyrazine derivatives.

Some compounds of Cephalostatin family have shown anti-cancer activity against human cancer cell line and active intensity has close with the stereochemistry of the substituted group, for example, beta-OH at C-12 in compound 2 showed less promising results and the mixture 3 (alpha + beta) showed a large enhancement of the activity compared to the compound 2. So, the work was concentrated on the synthesis diastereomers 10 and 11 were obtained in a pure form.