Nitrone dipolar cycloaddition routes to piperidines and indolizidines. Part 9.Part 8. See Ref. 22. Formal synthesis of (–)-pinidine and total synthesis of (–)-histrionicotoxin, (+)-histrionicotoxin and (–)-histrionicotoxin 235AThis manuscript is dedicated to the sixtieth birthday of Professor L. Tietze.