A Novel Deoxygenation of Hydroxy Groups Activated by a Vicinal Carbonyl Group via Reaction with Ph3P/I2/Imidazole
摘要:
A new procedure for a direct conversion of an alpha-hydroxy sugar ester, lactone or amide into the corresponding alpha-deoxyester , lactone or nitrile using the system Ph-3/I-2 /imidazole is reported. Its efficiency is illustrated by deoxygenation in good yields at position 2 of methyl 3,4:5,6-di-O-isopropylidene-D-gluconate (1), and at positions 5 of 3-O-benzyl-1,2-O-isopropylidene-alpha-D-glucofuranuronamide (3) and 1,2-O-isopropylidene-alpha-D-glucofuranurono-6,3-lactone (5). Reaction with 5,6-O-isopropylidene-L- and -D-gulo-1,4-lactones (7) and (9), respectively, afforded the corresponding alpha,beta-unsaturated lactones in good yields.
A Novel Deoxygenation of Hydroxy Groups Activated by a Vicinal Carbonyl Group <i>via</i> Reaction with Ph<sub>3</sub>P/I<sub>2</sub>/Imidazole
作者:Amélia P. Rauter、Ana C. Fernandes、José A. Figueiredo
DOI:10.1080/07328309808001882
日期:1998.9.1
A new procedure for a direct conversion of an alpha-hydroxy sugar ester, lactone or amide into the corresponding alpha-deoxyester , lactone or nitrile using the system Ph-3/I-2 /imidazole is reported. Its efficiency is illustrated by deoxygenation in good yields at position 2 of methyl 3,4:5,6-di-O-isopropylidene-D-gluconate (1), and at positions 5 of 3-O-benzyl-1,2-O-isopropylidene-alpha-D-glucofuranuronamide (3) and 1,2-O-isopropylidene-alpha-D-glucofuranurono-6,3-lactone (5). Reaction with 5,6-O-isopropylidene-L- and -D-gulo-1,4-lactones (7) and (9), respectively, afforded the corresponding alpha,beta-unsaturated lactones in good yields.
Synthesis and structure of d-glucuronolactone derived carboxamides
作者:Saravanan Kandasamy、George F.S. Whitehead、Iñigo J. Vitórica-Yrezábal、John M. Gardiner
DOI:10.1016/j.carres.2023.108744
日期:2023.2
observed as competing processes. This is not seen the using 5-O-PMB protection which the provides the method of choice for obtaining a fully protection-differentiated glucofuranamide. X-ray crystal structures of a fully-protected glucurono-6,3-lactone lactone and a glucuronamide derivatives are reported.