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Expedient and practical new methodology for the synthesis of substituted imidazoles was developed to provide a rapid access to a variety of 2-substituted, 1,2-disubstituted and 1,2,4-trisubstituted imidazoles by the direct CuCl-mediated reaction of nitriles with α-amino acetals in an intermolecular as well as intramolecular fashion.

A practical, one-step process for the synthesis of 2,5-disubstituted pyrimidines is presented. The protocol proved to be general for the synthesis of a variety of pyrimidine-containing compounds bearing an assortment of functional groups.

The formation of five- and six-membered rings using cyclization reactions terminated by enamides and enecarbamates is described.

The Lewis acid-promoted intramolecular formal [3+2]-atom «cycloaddition» of alkenes with benzylic cations derived from benzylic alcohols and quinone methides affords products in good yield and with remarkable stereoselectivity. Benzylic alcohol 20 affords hexahydrofluorene 36 with three new stereogenic centers in 73% yield as a 10:1 mixture of diastereomers. The scope and limitations of these reactions were explored by varying the substitution pattern on the benzylic cation, the cyclization initiators, and the alkene terminators

A route towards the synthesis of a ranitidine bulk drug product impurity is described. This protocol involves acetyl chloride initiated oxonium ion generation and subsequent trapping to form the corresponding ranitidine dimer ( 1 ). This synthesis allowed for structure verification of the impurity and provided reference supplies for further analytical and toxicology investigations.

The synthesis of chiral, nonracemic, fully protected α,α-disubstituted α-amino acids via the Beckmann rearrangement of tosylated oximes 1 is described. The desired amino acids were obtained in good yields with excellent enantioselectivities in relatively few steps.

A study to reach the diterpenoid (+)-triptoquinone A (3) or its analog (+)-triptinin A (4) via an asymmetric tandem addition to naphthyloxazolines is described. The tandem addition to the chiral dihydronophthalene 6 resulted in a 70% yield of single diastereomer 10. Further manipulation gave the natural products' tricyclic ring system, compounds 20 and 29 via ring-closing metathesis in 90% yield, using the Schrock catalyst. Final assault to the target compounds 3 or 4 fell short due to the failure to either reduce a neopentyl hydroxymethyl group to a methyl or to install the conjugated carboxylic acid present in 3 or 4.