Catalytic Hydrogenation of Substituted 15β-Pregn-16-enes

摘要

The catalytic hydrogenation of 15-benzoyloxybutyl-20-hydroxymethylpregn-16-enes under various conditions was studied. It was shown that at the use of a palladium catalyst along with the reduction of the double bond also its shift occurred giving △~(14)-derivatives. The reduction over a platinum catalyst is accompanied by the saturation of aromatic ring of the protecting group, but gives the best yield of the desired products and provides a preparative approach to 15-substituted analogs of brassinosteroids. The structures of the obtained compounds were proved by two-dimensional NMR spectroscopy and HPLC-MS.