The Transformation of Jervine into 18-Functional C-Nor-D-homosteroids

Article abstract of DOI:10.1246/bcsj.53.210

N,O-Diacetyldeoxojervine, obtained by the Wolff-Kishner reduction of jervine followed by acetylation, has been catalytically hydrogenated to (22S,25S)-N,3-O-diacetyl-5α-veratranine-3β,23β-diol.Irradiation in benzene containing mercury(II) oxide and iodine afforded 20-formyl-17β-ethyl-12α-etiojervan-3β-ol 3-acetate which was converted into 17β-ethyl-3β-hydroxy-12α-etiojervan-20-one 3-acetate by dye-sensitized photo-oxygenation of the corresponding morpholine enamine.Reduction to 17β-ethyl-12α-etiojervane-3β,20β-diol 3-acetate with sodium borohydride followed by irradiation in benzene in the presence of mercury(II) oxide and iodine afforded an 18-functional C-nor-D-homosteroid, (20R)-18,20-epoxy-17β-ethyl-12α-etiojervane-3β,20β-diol.The configuration of the methyl group on the tetrahydrofuran ring has been shown to be α on the basis of the NMR spectrum, confirming a previous assignment.