Epoxy Metradiene synthesis

Yield:83873-16-9 92%

Reaction Conditions:

Stage #1: 6α-methyl-17α-hydroxy-pregna-1,4,9(11)-triene-3,20-dionewith perchloric acid;1,3-dibromo-5,5-dimethylimidazolidine-2,4-dione in water;acetone at 25; for 4.5 h;
Stage #2: with water;potassium carbonate in acetone; for 4 h;stereoselective reaction;

References:

Marcos-Escribano, Andrés;Bermejo, Francisco A.;Bonde-Larsen, Antonio Lorente;Retuerto, Jesús Iglesias [Tetrahedron,2009,vol. 65,# 41,p. 8493 - 8496] Location in patent:experimental part