Bile acids LXIX. Selective K-Selectride reduction of 3,7-diketo steroids

The K-Selectride reduction at low temperature (-45°C) of 7-oxo-5α-holestan-3β-yl acetate and methyl 7-oxo-3α-hydroxy-5(β-cholanoate resulted in almost quantitative yield of the 7α-alcohol in the 5α-compound but only moderate yield of the 5β-analog. The simultaneous reduction of two carbonyl groups in the 3 and 7 positions afforded good to excellent yields of the diaxial diol in planar steroids (methyl 3,7-dioxo-5α-cholanoate, 3,7-dioxo-5α-cholestane and methyl 3,7-dioxo-5α-cholestan-27-oate) and only 14% of 3α,7α-(OH)₂ from methyl 3,7-dioxo-5β-cholanoate.     

The conformation of 3-acetyl-Δ3-carene and 3-carene-7-al

Conclusions The conformations of 3-acetyl-³-carene and 3-carene-7-al were established on the basis of the spectral data and molar Kerr constants.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 994–998, May, 1971.