Synthesis of 20α-Hydroxy-16-oxosteroids and the C-20 Configuration of Δ<SUP>17(20)</SUP>-16-Ocosteroids
作者:Shunsaku Noguchi、Masayuki Imanishi、Katsura Morita
DOI:10.1248/cpb.12.1184
日期:——
Treatment of 16β, 20α-dihydroxysteroids, Ia, Ib, and Ic, with Na2Cr2O7-H2SO4 reagent in ether-benzene-tetrahydrofuran resulted in a selective oxidation of the 16-hydroxyl group to afford 20α-hydroxy-16-oxosteroids, IIIa, IIIb, and IIIc. IIIa, IIIb, and the 20-acetates, IVa and IVb, were treated with TsCl, KHCO3, K2CO3 or alumina to afford a mixture of cis and trans 17(20)-16-oxosteroids (V and VI). The C-20 configuration of the isomers, V and VI, was established on the basis of the nuclear magnetic resonance spectra.
用 Na2Cr2O7-H2SO4 试剂在乙醚-苯-四氢呋喃中处理 16β、20α-二羟基类固醇 Ia、Ib 和 Ic,可选择性地氧化 16-羟基,得到 20α-羟基-16-类固醇 IIIa、IIIb 和 IIIc。IIIa、IIIb 以及 20-乙酸酯 IVa 和 IVb 经 TsCl、KHCO3、K2CO3 或氧化铝处理后,可得到顺式和反式 17(20)-16- 氧固醇混合物(V 和 VI)。根据核磁共振光谱确定了异构体 V 和 VI 的 C-20 构型。