ASYMMETRIC SYNTHESIS OF BIOLOGICALLY IMPORTANT ALKALOIDS

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We propose to further develop, refine, and test new methods for the stereoselective alkylation, alpha to nitrogen, of a number of heterocyclic systems affording alkaloids and other amines in excellent chemical and optical yields. Several of these methods are unprecedented, and all afford access to classes of compounds which are important because of their unique structural features and /or their pivotal role in chemistry and biochemistry. The new dipole-stabilized anion precursors will be investigated as potentially useful synthetic tools in acyclic stereoselection. The asymmetric alpha, alpha'-dialkylation of isoindoline affords access to a unique class of chiral 2 degree amines having C2 -symmetry. The use of these 2 degree amines as enantioselective bases will be examined, as well as their use as chiral adjuvants in several other asymmetric processes. We propose to evaluate other aminooxazolines as chiral adjuvants, and to continue our efforts to elucidate the mechanism of asymmetric induction in dipole-stabilized anion systems.