Synthesis and structure of 2-pyransoylperimidines

The first examples of 2-pyranosylperimidines are reported. The β-d-glucopyranosyl nitrile oxide 5, generated by base-induced dehydrochlorination of the hydroximoyl chloride 4, reacted with 1,8-diaminonaphthalene to afford the 2-(β-d-glucopyranosyl)perimidine 8. The d-xylo-, d-galacto-, d-manno- and d-glycero analogues 12, 15, 16 and 19 were prepared similarly. The glycals 9 and 13 were formed as by-products resulting from elimination of acetic acid from the corresponding pyranosylperimidines. The structure of d-glucose-derived perimidine 8 was established by X-ray crystallography.