Showing papers by "Kunisuke Izawa published in 1998"
TL;DR: Several processes leading to known antiviral agents starting with guanosine are developed, which involve enzymatic transglycosylation for stavudine (d4T), chemical transpurination for acyclovir and ganciclovir, and novel alkylauon for pencic Lovir and famciclovIR.
Abstract: Guanosine produced by fermentation is one of the nucleosides most readily available on an industrial scale. We have recently developed several processes leading to known antiviral agents starting with guanosine. The processes involve enzymatic transglycosylation for stavudine (d4T), chemical transpurination for acyclovir and ganciclovir, and novel alkylauon for penciclovir and famciclovir.
20 citations
2 citations
Patent•
05 Nov 1998TL;DR: In this article, a simple and inexpensive method for producing α-hydroxy-β-aminocarboxylic acids and their esters is presented, where an ester of an N-protected α-amino acid ester is converted into a β-ketosulfoxide, which is then processed with an acid to give an α-ketohemimercaptal.
Abstract: The present invention provides a simple and inexpensive method for producing α-hydroxy-β-aminocarboxylic acids and their esters. An ester of an N-protected α-amino acid ester is converted into a β-ketosulfoxide, which is then processed with an acid to give an α-ketohemimercaptal. Next, this is acylated and then processed with a base to obtain an N-protected α-acyloxy-β-amino-thioester, which is then saponified to obtain an intended compound. According to the method of the present invention, it is possible to produce α-hydroxy-β-aminocarboxylic acid derivatives, which are intermediates in producing various HIV protease inhibitors, renin inhibitors and carcinostatics, from a-amino acids. The method comprises reduced reaction steps, the selectivity in the method to give the intended product is high, and the yield of the product obtained is high.