SYNTHESIS OF GONA-3,5-DIENES AND STUDIES ON THEIR ACTIVITY FOR INTERRUPTION OF EARLY PREGNANCY

A series of gona-3,5-dienes were synthesized from norgestrel, norethisterone 17α-hydroxyprogesterone and ethisterone via reduction of α,β-unsaturated 3-ketones to allylic alcohols and dehydration with concomitant migration of the double bond. The structures of these gona-3,5-dienes were verified by MS and ¹H-NMR spectral data.Pharmacological results showed that compound IV_b2 in this series gave rise to significant interruption of early pregnancy in mice. The mechanism of the early pregnancy terminating effect of this compound was discussed.