This report continues our work on the synthesis of heterocyclic compounds from saccharide derivatives1-7. Recently, 2-methyl-5-(D-arubino-tetrahydroxybutyl)-3furoylhydrazine was condensed6 with a series of aldehydes to give the corresponding N '-arylidene-N-[2-methyl-5-(D-arabino-tetrahydro~butyl)-3-furoyl]hydrazones (l-4). We have now cyclized these compounds with acetic anhydride to 3-(4-acetyl-5-aryl-1,3,4,-oxadiazolin-2-yl)-2-methyl-5-(~-arubino-tetraacetoxybutyl)furans (S-81, which could be isolated in yields ranging from 20 to 38% (Scheme 1). The structure of these oxadiazoline derivatives was established by their forming O-deacetylated products 9-12 when treated with either 3% NaOMe or NH,OH. The structures were also confirmed by IR and 'H NMR spectroscopy, wherein the C=N, NAc, and OAc bands appeared at the expected frequencies, and all protons showed appropriate resonances in their 'H NMR spectra (for details, see Table I and the Experimental section).
Periodate oxidation of hydrazone 4 afforded the corresponding formyl deriva-tive6 13, which condensed with a number of aroylhydrazines to furnish the corresponding new aroylhydrazones 14-19 (Scheme 1). As expected, the IR spectra showed the disappearance of the aldehydic band (for details, see the Experimental section and Table I). N-[5-Formyl-(p-toluoylhydrazone)-2-methyl-3furoyllcinnamaldehyde-hydrazone (15) underwent cyclization with iodine and yellow mercuric oxide in the presence of magnesium oxide at room temperature to afford 2-methyl-3- [5-styryl-(l,3,4-oxadiazol-2-yl)l-5-[5-(p-tolyl~-(1,3,4-oxadiazol-2yl)]furan (20) (Scheme 1). The IR spectrum revealed the disappearance of both the NH and CO bands (for details, see the Experimental section). EXPERIMENTAL General methods.-Melting points were determined on a Kofler block and are uncorrected. IR spectra were recorded on Unicam SP 1025 and SP 2000 spectrophotometers.
'H NMR spectra were recorded with a Varian EM-90 instrument