Development of new synthetic methodology and enantioselective synthesis of the A-B-C ring system of the Veratrum alkaloids

This work is divided into four chapters spanning three projects. The first two projects involve new synthetic methodology and the third uses synthetic protocols developed in our lab towards the total synthesis of a natural product.;The first project describes the practical synthesis of a geometrically defined diiodo compound for use in organic synthesis. Most allylic iodides are subject to decomposition and are difficult to handle. An improved method for purification and isolation is described. Several derivatives were also prepared to display the synthetic utility of the diiodide.;A new route to enantiomerically pure alpha-amino acids is described in the second chapter. This route is based on esterification of the carboxylic acid with L-menthol, followed by diazo transfer and NH insertion into o-anisidine. This protocol allows for either enantiomer of the amino acid to be produced. The intermediates in the synthetic route can be monitored for diastereomeric purity by 1H-NMR.;The final chapter describes a new route to the 6-6-5 system of the Veratrum alkaloids using an approach developed in our lab. A two step process of asymmetric allylation followed by an oxy-Cope rearrangement gave rise to an enantiomerically pure alpha,beta-dialkyl ketone. A Robinson annulation was then used to form the 6-6 bicyclic system. A rhodium catalyzed CH insertion was employed to construct the third ring. A model route for the endgame of the synthesis of (-)-veratramine was also developed.