Dept. of Chemistry and Biochemical Sciences
Oregon Graduate Center
An efficient, regiospecific, high yield method for preparing racemic daunosamine, 3-epidaunosamine, ristosamine, vancosamine, and 3-epivancosamine from achiral precursors is described. The methodology involves preparation of a 6-carbon diene fragment with either a C-1 or C-5 hydroxyl group which is transposed to a C-3 amide through Claisen rearrangement of a imidate intermediate. C-1 of the terminal olefin is converted to a latent aldehyde group through Pummerer rearrangement of a 1-phenylthio sulfinyl group. Regio- and stereospecific functionalization of the 4,5-double bond either through cis-hydroxylation or epoxidation followed by hydrolysis with concomittant ring closure provides the desired sugars in good overall yield. In order to demonstrate the versatility of this route, four aminopentose analogues were prepared in a similar manner through azetidinone intermediates. The Ã-lactams were prepared from volatile olefins using an improved procedure to provide the azetidinones in good yield (93-98%). Conversion of the azetidinones to the aminopentoses was accomplished in a straightforward manner.
Ellenberger, Suzanne Ray, "Total synthesis of selected deoxyamino sugars" (1986). Scholar Archive. 207.