Two step synthesis of D- and L- &agr;-amino acids and D- and L- &agr;-amino aldehydes
D- and L- &agr;-amino acids and D- and L-&agr;-amino aldehydes are synthesized from olefin substrates in two steps. The first step is a catalyzed asymmetric aminohydroxylation addition reaction to the olefin substrate. The addition reaction is catalyzed by osmium and is co-catalyzed by chiral ligands. The chiral ligands, in addition to being co-catalysts with the osmium, also serve to direct the addition reaction regioselectively and enantioselectively, divalent ligands are preferred over monovalent ligands because of their enhanced regio-and enantio-selectivity. As an oxidant nitrogen source for the addition reaction, either a carbamate or sulfonamide may be employed. If carbamate is employed as an oxidant nitrogen source, the resultant &bgr;-hydoxycarbamate is deprotected to yield the corresponding &bgr;-hydroxyamine. If sulfonamide is employed as an oxidant nitrogen source, the resultant &bgr;-hydroxysulfonamide is deprotected to yield the corresponding &bgr;-hydroxyamine. The resultant &bgr;-hydroxyamine is then selectively oxidized in a second synthetic step to produce the desired D- and L- &agr;-amino acid or D- and L-&agr;-amino aldehyde.
The Scripps Research Institute
C
C07C
inventional
Guigen K. Barry
Li Sharpless