[EN] NEW MONO-AND BISMETHYLENE-STEROID DERIVATIVES AND PROCESS FOR THEIR SYNTHESIS [FR] NOUVEAUX DERIVES DE MONO-ET BISMETHYLENE-STEROIDE ET PROCEDE DE SYNTHESE DE CEUX-CI
[EN] NEW MONO-AND BISMETHYLENE-STEROID DERIVATIVES AND PROCESS FOR THEIR SYNTHESIS [FR] NOUVEAUX DERIVES DE MONO-ET BISMETHYLENE-STEROIDE ET PROCEDE DE SYNTHESE DE CEUX-CI