metabolite 4 showed an additional methine signal at d 4.49, which
indicated hydroxylation of danazol (1) (Table 1). The 13C NMR
spectrum also showed signals for an oxymethine carbon at d 72.6
(Table 2). This supported hydroxylation of substrate 1. The position
of OH at C-6 was deduced through HMBC correlations of H2-7
(d 1.95 and 1.21) with C-6 (d 72.6) and C-5 (d 155.6) (Fig. 2). The
stereochemistry of OH at C-6 was deduced through NOESY
correlations between H-6 and H-4. The H-6 can only show correlation
with H-4, if it is equatorially oriented. Therefore a b-OH was
placed at C-6 (Fig. 3). The structure of new compound 4 was thus
deduced as 6b,17b-dihydroxy-17a-pregna-2,4-dien-20-yno-[2,3-
d]-isoxazole.
Metabolite 5 was obtained as a white powder. The molecular
formula C22H28O3 of compound 5 was deduced on the basis of