NEW ASYMMETRIC PROCESSES FOR USE IN ORGANIC SYNTHESIS

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This research seeks to discover and develop new asymmetric processes for use in the synthesis of enantiomerically pure organic substances. To the extent that this aim is realized, the syntheses of many fine chemical products, especially pharmaceuticals, will be simplified. About a year ago, under support by this grant, we discovered a general catalytic method for the asymmetric dihydroxylation (ADH) of olefins. At the heart of this proposal are the plans for developing this new asymmetric process. A major effort will be directed toward finding even better asymmetric ligands while at the same time trying to achieve the mechanistic insight which will make the ligand-design work more rational. The ADH process is also being extended to the area of catalytic oxyamination. The substrate scope of the process will be carefully examined. At present almost any olefin is a possible candidate since the asymmetric induction does not depend on prior binding of the substrate to the catalyst. Synthetic applications for the now readily available homochiral diols will receive emphasis. The main thrust relies on conversion of the diols into epoxide-like synthons, such as 1,2-cyclic sulfates. This work has a "synthetic methods" orientation but also includes planned syntheses of various biologically active substances (e.g. beta-lactams, diltiazem, brassinolide, antibiotic AT-125, cianidanol, etc.). Homochiral diols of C2 symmetry are now easily prepared and will be examined as chiral auxillaries/ligands for other asymmetric processes. Encouraged by the successful asymmetric dihydroxylation of isolated olefins, a continuing long-range goal of this project is asymmetric epoxidation of isolated olefins.