抄録
From the 70% (w/w) HClO4 solution saturated with testosterone (I) at room temperature, colorless needles, of 1 : 1 complex (II) of I and HClO4 were isolated. When 0.2% (w/v) chloroform solution of I was heated with the equal volume of HClO4 under nitrogen stream for 30 min at 60-65°, the steric isomers (m/e=272) of 17-methyl-18-norandrost-4-en-3-one (III) were obtained from the organic layer. The deep-green acid layer gave the mixture of 17-methyl-18-norandrosta-4, 13 (17)-dien-3-one (IV) and 17-methyl-18-norandrosta-4, 13 (14)-dien-3-one (V). Standard specimens of IV and V gave easily the similar absorption spectra to that (Fig. 1) due to I, when they were dissolved in the dichloromethane solution saturated with HClO4. The dienones, IV and V, also gave the same spectra even in the moderately acidic conditions where I still remained inert. Partially hydrogenated product (III), on the contrary, failed to show any visible light absorption in the acid medium. It seems that the isomeric olefins, IV and V, are the intermediates in the present chromogenic reaction and the carbonium ions (VIII) formed by the protonation of them may play an essential part in producing the chromophore.
