Bridged ring systems. Part XVI. A synthetic approach to lycopodium alkaloids
Abstract
A novel ring annelation technique has been devised to convert 9-oxobicyclo[3,3,1]non-3-ene-1-carboxylic acid (3; R = CO2H) intoN-acetyl-2-azatricyclo[5,3,3,01,6]tridecane (2; R = Ac), which comprises three rings of the tetracyclic system of lycopodine (1). Further progress towards the application of this annelation to a stereo-selective synthesis of lycopodine is described.