BICYCLIC SYSTEMS RELATED TO TAXOL - A DIRECT MEANS FOR IMPLEMENTING C-2 OXYGENATION AND DEMONSTRATION OF THE FEASIBILITY OF ALPHA-KETOL EQUILIBRATION IN A FULLY OXYGENATED B-RING SETTING

The feasibility of alpha-ketol equilibration in a fully oxygenated B-r ing setting for the rapid, enantioselective construction of an A/B bic yclic model related to Taxol has been examined. The key elements assoc iated with this successful venture include selection of a proper array of protecting groups for the four hydroxyl groups present, suitable c atalysis of the 1,2-pinacol-like shift, and an intrinsic dependence on the thermodynamic stabilities of the two alpha-ketol isomers. The key conversion of 13 to 14 is seen to be unidirectional and consequently to offer useful potential serviceability as more advanced thrusts towa rd Taxol are mounted.