Synthesis of new spiro-steroids, II: steroid-17-spiro-oxazolidinones

New, potential aldosterone blocking 17-spiro-oxazolidinone derivatives with androstane, estrane and 13 beta-ethyl-gonane ring system were synthesized. 17S-Spiro-oxiranes were used as starting compounds and the oxazolidinone ring was built up in different ways. All compounds but one were devoid of considerable endocrine activities. 3-Oxo-13 beta-ethyl-gona-4,9(10),11-triene-17S-spiro-5'-(2'-oxo-3'-methyl)oxazolidine shows significant antiandrogen activity on s.c., but none on p.o. administration.