Chevron Science Center 219 Parkman Avenue
Pittsburgh, PA 15260
Development of New Synthetic Methods and Mechanistic Organic Chemistry
Our synthetic mode involves: (1) the design of new chemical reactions often based on our mechanistic studies; (2) sequencing these so as to produce new synthetic methodology; (3) the application of the latter to particularly novel and efficient syntheses of natural products.
The discovery that aromatic radical-anions can reductively cleave C-S bonds has led to some of the most versatile methods known for producing carbanions for synthetic purposes, including the simplest and most general procedures for producing α-lithioethers, α-lithiosilanes, cyclohexenyl- and cycloheptenyllithiums, homoallyllithiums, and allyllithiums. In the latter case, considerable regiochemical and stereochemical control can be exerted. One use of these allyllithiums is in the Li-ene cyclization, eventually leading to our study of the analogous Zn-ene cyclization, resulting in perhaps the most efficient synthesis of (-)-kainic acid 1 (see below); an improved procedure that avoids the partial racemization occurring in one of the steps is being developed.
The use of a δ-lithiooxyanion in the most efficient synthesis from commercially available materials of the bee pheromone 2 in its natural pure enantiomeric state is shown.
Ramsay Memorial Fellow (Great Britain), 1955-56
Chancellor's Distinguished Research Award, University of Pittsburgh, 1992
The Pittsburgh Award, Pittsburgh Section, American Chemical Society, 2009.