287733-95-3Relevant academic research and scientific papers
An unexpected rearrangement during Mitsunobu epimerization reaction of sugar derivatives
Persky, Rachel,Albeck, Amnon
, p. 3775 - 3780 (2000)
Mitsunobu reaction on the glucose derivative (3S,4R,5R,6R)-3,4,5,7- tetrabenzyloxy-6-hydroxy-1-heptene yielded an unexpected rearrangement major product. Its structure was determined as (3R,4R,5R,6S)-4,5,6,7- tetrabenzyloxy-3-hydroxy-1-heptene. The suggested rearrangement mechanism involves an initial intramolecular cyclization, followed by ring opening by the nucleophile p-nitrobenzoate. Product distribution of the Mitsunobu reaction was substrate-dependent, with the corresponding mannose derivative (the 3R epimer) giving less of the initial intramolecular reaction products and the corresponding galactose derivative (the 5S epimer) yielding almost exclusively the expected epimerization product. Varying the Mitsunobu reaction conditions (addition of base and using nonpolar solvent) led to the expected epimerization product of the glucose derivative.
Synthesis of Selectively Labeled D-Fructose and D-Fructose Phosphate Analogues Locked in the Cyclic Furanose Form
Persky, Rachel,Albeck, Amnon
, p. 5632 - 5638 (2007/10/03)
2,5-Anhydroglucitol and 2,5-anhydromannitol and their 6-phosphate and 1,6-diphosphate derivatives are cyclic analogues of the α and β anomers of D-fructofuranose, D-fructofuranose-6-phosphate, and D-fructofuranose-1,6-diphosphate. They were synthesized from protected D-mannose or D-glucose. The synthetic method was developed with emphasis on selective 2H labeling of these compounds, as a model for 3H incorporation, which will be used for further biochemical studies. A key cyclization step, based on a benzyl ether nucleophilic attack on an activated alcohol, constructed the ring system. The stereochemistry at C2 (α/β anomers) and at C5 (D sugar) was controlled by selective epimerizations. Mono- and diphosphate analogues were obtained from the same intermediate by changing the sequence of deprotection and phosphorylation steps.
