NEW BIS- AND TRIS-ANNULATION REAGENTS FOR THE SYNTHESIS OF CD RINGS OF STEROIDS, BEARING A FUNCTIONALIZED 18-METHYL GROUP, BY THE PALLADIUM CATALYZED CYCLIZATION

Article abstract of DOI:10.1016/S0040-4039(00)78697-7

2-Substituted 2-alkoxycarbonyl-3-vinylcyclopentanones (2), easily prepared by the palladium-catalyzed cyclisation of 2-substituted 3-oxo-8-phenoxy-6-octenoates (1), are very suitable building blocks for CD rings of steroids, bearing particularly a functionalized l8-methyl group.