The more stable compound, 9, 14α-epoxy-3-methoxy-8, 14-secoestra-1, 3, 5 (10)-trien-17-one (IVa), given by cyclization of 14α-hydroxy-3-methoxy-8, 14-secoestra-1, 3, 5 (10), 9-tetraen-17-one (II), has been assigned to a 9α, 14α-epoxy compound (9S configuration).
