Methanol → (3S,8R,9S,10R,13S,14S,17S)-10,13-Dimethyl-7-oxo-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthrene-3,17-diyl diacetate

関与物質

反応条件

反応手順

37.4 g (0.1 mol) 3β,17β-diacetoxyandrost-5-ene (Steraloids A7850) in 400 ml glacial acetic acid was reacted with 30.06 g (0.3 mol) chromium(VI) oxide (Aldrich 23,265-3) dissolved in 20 ml H2O and 20 ml glacial acetic acid by the method of Butenandt (op. cit.). The CrO3 solution was added dropwise over 4 hours to the 3β,17β-diacetoxyandrost-5-ene solution while maintaining the temperature at 55° C. At the end of that time methanol was added to the reaction mixture in order to decompose any unreacted CrO3, followed by aqueous salt solution and ether. Evaporation of the ether yielded 7.8 g (20% yield) of crude III. Crystallization from 95% EtOH yielded (III) m.p. 214°-215° C. [218°-219° C., Butenandt, op. cit.; 224°-225° C. (from methanol), Pearson et al., J. Chem. Soc. Perkin Trans., I, 267-273 (1985 )] DSC peak 191°-224° C., max at 220° C. Normal phase tlc: EtOAC-cyclohexane-EtOH (45:45:10), Rf=0.86. IR bands: 1737, 1666 cm-1, (Pearson, op. cit. 1728, 1668).

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