Functionalized 2-Azabicyclo(3.3.1)nonanes. Part 16. Studies on the Synthesis of Strychnos Indole Alkaloids. An Efficient Stereocontrolled Synthetic Route to 2,4,8- and 2,8,9-Trisubstituted 2-Azabicyclo(3.3.1) nonan-7-ones.