UNSTABILIZED DIAZO DERIVATIVES FROM CARBOHYDRATES - APPLICATION TO THE SYNTHESIS OF 2-DEAMINO-TUNICAMINE AND PRODUCTS RELATED TO C-DISACCHARIDES

We applied a new synthetic method to C-disaccharides to obtain 2-deami no-tunicamine, the 2-hydroxy analogue of tunicamine, which is the main nucleus of tunicamycin antibiotics. iazo-1:2,3:4-di-O-isopropylidene- D-galactopyranose was synthesized and reacted with methyl opylidene-be ta-D-ribopentonodialdo-1,4-furanoside, to obtain a mixture of ketone a nd an epoxide with C-disaccharide structures. The epoxide was obtained in a reasonably good yield and full stereoselectivity, and was reduce d to protected 2-deamino-tunicamine. Reduction of the ketone isomer, y ielded the 7-epimer of 2-deamino-tunicamine. This is the first reporte d instance of an epoxy-C-disaccharide, the primary interest of which l ies in its potential inhibition of glycosidase enzymes.