Abstract
The Oppenauer oxidation product (II) of purpnigenin (I) was assumed to be 14, 15-dihydroxyprogesterone and, therefore, two kinds of 14, 15-dihydroxy compound (VI and VIII) were synthesized from progesterone (III) to compare with (II). Oxidation of ⊿14-progesterone (V) with osmium tetroxide produced 14α, 15α-dihydroxyprogesterone (VI) which did not agree with (II). Oxidation of (V) with peracid and cleavage of the epoxide thereby obtained with perchloric acid produced 14, 15-dihydroxypregn-4-ene-3, 20-dione (VIII) which was identified with (II). This has proved that (II) is 4-pregnene-14, 15-Consequently, the original purpnigenin is considered to be 3, 14, 15-trihydroxypregn-5-en-20-one. The two hydroxyls at 14-and 15-positions are considered to be trans-diols but further examination will have to be made as to their exact configuration. It is interesting that pregnenolone, hitherto considered as animal constituent, has now been found in a plant as an aglycone.
