Collect. Czech. Chem. Commun. 1979, 44, 2156-2160

Model experiments in the synthetic approach to strophanthidin: The synthesis of 3β,5-dihydroxy-5β-cholestan-19-al

Pavel Kočovský

Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, 166 10 Prague 6


A five step synthesis of the title compound XV as a model substance for simple construction of the A/B ring part of strophantidin (I) is described. The key step of this synthetic approach is the hypobromous acid addition to the formate V which gives predominantly the diequatorial bromohydrin X as a result of 6(O)π,n participation of the 19-ester group in 5α,6α-bromonium ion VII cleavage. Treatment of X with Raney-Ni yields the 19-hydroxy derivative XII which on oxidation and hydrolysis gives the aldehyde XV.