Deoxyhydantocidin: Synthesis by Base-Catalyzed Spiro Cyclization and Interconversion with the 1′-Epimer

Synthesis and herbicidal activity of 5-(4-hydroxybenzyl)-2-thioxoimidazolidin-4-one esters

A series of novel 5-(4-hydroxybenzyl)-2-thioxoimidazolidin-4-one esters were synthesized under mild conditions by the reaction of 5-(4-hydroxybenzyl)-2-thioxoimidazolidin-4-one and carboxylic acids with DCC and DMAP as the promoters. Their structures were confirmed by ¹H-NMR, IR, ESI-MS and elemental analysis. The preliminary bioassy results indicated that some of compounds exhibit good herbicidal activity against Zea mays, Triticum aestivum and Arabidopsis thaliana. The further greenhouse test showed that compounds 6-16 and 6-28 have 60%, 50% and 50% efficacy against Stellaria media, Echinochloa crus-galli and Setaria viridis at 1,000 g/ha, respectively.

Synthesis of some derivatives of C-(1-deoxy-1-N-substituted-d-glucopyranosyl)formic acid (d-gluco-hept-2-ulopyranosonic acid) as potential inhibitors of glycogen phosphorylase

Per-O-benzoylated derivatives (amide, methyl ester and glycinamide) of C-(1-azido-1-deoxy-alpha-D-glucopyranosyl)formic acid obtained by azide substitution in the corresponding C-(1-bromo-1-deoxy-beta-D-glucopyranosyl)formic acid derivatives were debenzoylated by the Zemplén-protocol. Per-O-benzoylated C-(1-azido-1-deoxy-alpha-D-glucopyranosyl)formamide was dehydrated by oxalyl chloride-DMF to give the corresponding nitrile, while from its reduction mixture obtained by Raney-nickel or sodium hydrogentelluride C-(1-amino-1-deoxy-beta-D-glucopyranosyl)formamide could be isolated. Acetylation of this amino-amide by Ac2O/Py and subsequent debenzoylation gave C-(1-acetamido-1-deoxy-beta-D-glucopyranosyl)formamide. Applying the same conditions to the crude reduction mixture allowed the alpha-anomer to be isolated as a minor component. An alternative pathway to produce the above beta-anomer appeared in the reaction of C-(1-bromo-1-deoxy-beta-D-glucopyranosyl)formamide with CH3CN in the presence of Ag2CO3 to yield 1-acetamido-2,3,4,6,-tetra-O-benzoyl-1-deoxy-beta-D-glucopyranosyl cyanide, which was hydrated, in the presence of TiCl4, to the formamide. Some of the new compounds were shown to be weak inhibitors of muscle glycogen phosphorylase b.

Synthesis and properties of spiro nucleosides containing the barbituric acid moiety

The two chiral spiro nucleosides 4 and 5 containing the barbituric acid moiety were efficiently synthesized from optically pure precursors, and their properties were studied. The carbocyclic nucleoside 5 is considerably more stable against ring opening than the deoxyribosyl derivative 4. Both compounds present enhanced hydrogen bonding capacity with diacetyladenosine.