[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 17 alpha-hydroxyprogesterone and ethisterone via reduction of alpha, beta-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 IVb2 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.