Synthesis of natural and unnatural products by elaboration of alpha-chloroaldehydes

Fitting broadly under the category of target-oriented synthesis of complex organic molecules, the work described in this document pertains primarily to exploiting the facile organocatalytic synthesis of enantiomerically enriched α-chloroaldehydes, drawing out their potential through conversion into 1,2-chlorohydrins, and exploring the means by which these substances may be coerced to undergo intramolecular cyclization involving a nitrogen nucleophile. Specific targets and methodology include a successfully completed synthesis of the natural product (+)-preussin and similarly substituted pyrrolidines through the reductive annulation of β-iminochlorohydrins, a formal synthesis of (-)-swainsonine and related alkaloids through a related intramolecular cyclization strategy, and the synthesis and structural analysis of a carbocyclic mechanism-based inactivator of a glycoside hydrolase. As a secondary focus, this thesis also describes the isolation, structural elucidation, and testing of the long-range sex pheromone of the strepsipteran Xenos peckii, which was ultimately determined to be (7E,11E)-3,5,9,11-tetramethyltridecadienal, and of the chemical constituents of the bed bug (Cimex lectularius) aggregation pheromone, which were ultimately determined to be dimethyl disulfide, dimethyl trisulfide, (E)-2-hexenal, (E)-2-octenal, 2-hexanone, and histamine.