Synthesis of and a comparative study on the inhibition of muscle and liver glycogen phosphorylases by epimeric pairs of D-gluco- and D-xylopyranosylidene-spiro-(thio)hydantoins and N-(D-glucopyranosyl) amides
D-Gluco- and D-xylopyranosylidene-spiro-hydantoins and -thiohydantoins were prepared from the parent sugars in a six-step, highly chemo-, regio-, and stereoselective procedure. In the key step of the syntheses C-(1-bromo-1-deoxy-β-D-glycopyranosyl)formami
A straightforward route to hydantocidin analogues with pyranose ring structure
Partial hydrolysis of the nitrile moiety in aeetylated 1-bromo-glycopyranosyl cyanides 1 and 9 mediated by TiCl4 gave C-(1-bromo-1-deoxy-glycopyranosyl) formamides 2 and 10 whose reaction either with AgOCN, AgSCN or KSCN in nitromethane resulted in the formation of glycopyranosylidene-spirohydantoins 3, 11 and 15 and -thiohydantoins 7 and 16. Zemplen-deacetylation gave the pyranoid epihydantocidin analogues 4 and 12, and thiohydantocidin analogues 8 and 17, respectively.