81748-27-8Relevant academic research and scientific papers
PREPARATION OF C-NUCLEOSIDES BY DEHYDRATION OF PENTAHYDROXYPENTYL-HETEROCYCLES: STERIC COURSE AND MECHANISM
Perez, Juan A. Galbis,Galan, Emilio Roman,Requejo, Jose L. Jimenez,Corrales, Florentino Polo
, p. 111 - 120 (1982)
The acid-catalysed dehydration of pentahydroxypentyl-heterocycles can take place between C-1' and C-4' to yield C-nucleosides having furanoid structures, or between C-1' and C-5' to yield pyranoid compounds.Each reaction can yield one of the two possible anomers or a mixture of both.We have dehydrated pentahydroxypentyl-heterocycles having D-gluco, D-manno, and D-galacto configurations.When the reactions were kinetically controlled, the 6,6-dimethyl-2-(pentitol-1-yl)-4,5,6,7-tetrahydroindol-4-ones having the D-gluco or D-manno configurations yielded 2-α-D-arabinofuranosyl-6,6-dimethyl-4,5,6,7-tetrahydroindol-4-one, but they yielded 2-α-D-arabinopyranosyl-6,6-dimethyl-4,5,6,7-tetrahydroindol-4-one under conditions of thermodynamic control.Dehydration of 3-acetyl-2-methyl-5-(D-galacto-pentitol-1-yl)-1-propylpyrrole gave a mixture of 3-acetyl-5-(α- and β-D-lyxopyranosyl)-2-methyl-1-propylpyrrole.These results are consistent with a mechanism involving an intermediate C-1' carbocation.
Studies on Anhydro-osazones. Part 5. Structure and Anomeric Configuration of the C-Nucleoside Analogues Obtained from the Dehydration of D-gluco- and D-manno-Hept-2-ulose Phenylosazones
Sallam, Mohammed A. E.
, p. 557 - 562 (2007/10/02)
Dehydration of D-gluco- and D-manno-hept-2-ulose phenylosazones with methanolic sulphuric acid afforded the anomeric furanosyl anhydro-osazone pair: 3,6-anhydro-D-manno-hept-2-ulose phenylosazone (2) and the gluco-analogue osazone (3).A new type of anomeric pyranosyl anhydro-osazone was also idenified.Refluxing the anhydro-osazones with copper sulphate afforded the anomeric furanosyl C-nucleoside analogues 4-α-D-arabinofuranosyl-2-phenyl-v-triazole (6) and the β-isomer (7), and the arabinofuranosyl isomers (8) and (9).The structures and anomeric configurations of the products were determined by periodate oxidation, o.r.d., and n.m.r. spectroscopy.The mechanism of the dehydration and the mass spectra of compounds (6)-(9) are discussed.
