STUDIES ON 3-EPIMERIC L-2-HEXULOSE PHENYLOSAZONES. STRUCTURE AND ANOMERIC CONFIGURATION OF THE 3,6-ANHYDRO-OSAZONE DERIVATIVES OBTAINED FROM L-xylo- AND L-lyxo-2-HEXULOSE PHENYLOSAZONE

Article abstract of DOI:10.1016/S0008-6215(00)88062-3

Dehydration of the 3-epimeric 2-hexulose phenylosazones L-xylo-hexulose phenylosazone and L-lyxo-hexulose phenylosazone afforded 3,6-anhydro-L-lyxo-2-hexulose phenylosazone (2) as the preponderant isomer from both.The identity of 2 was obtained by t.l.c., and by acetylation followed by comparison of the products.Acetylation of 2 with acetic anhydride-pyridine afforded the di-O-acetyl derivative 4, and further acetylation gave the N-acetyl-di-O-acetyl derivative 5.Refluxing of 2 with copper sulfate afforded a C-nucleoside analog, namely, 2-phenyl-4-α-L-threo-furanosyl-1,2,3-osotriazole (6).The anomeric configuration was determined by n.m.r. spectroscopy.The stereochemical course of the dehydration process and the mass spectra of compounds 2, 4, 5, and 6 are discussed.