TY - JOUR
T1 - A new look at acid catalyzed deacetylation of carbohydrates
T2 - A regioselective synthesis and reactivity of 2-O-acetyl aryl glycopyranosides
AU - Stepanova, Elena V.
AU - Nagornaya, Marina O.
AU - Filimonov, Victor D.
AU - Valiev, Rashid R.
AU - Belyanin, Maxim L.
AU - Drozdova, Anna K.
AU - Cherepanov, Victor N.
PY - 2018/3/22
Y1 - 2018/3/22
N2 - In the present work we report that acetyl groups of per – acetylated aryl glycosides have different reactivity during the acidic deacetylation using HCl/EtOH in CHCl3, which leads to preferential deacetylation at O-3, O-4 and O-6. Thereby, the one-step preparation of 2-O-acetyl aryl glycosides with simple aglycon was accomplished for the first time. It was proved that the found reagent is to be general and unique for the preparation of series of 2-О-acetyl aryl glycosides. We have determined the influence of both carbohydrate moiety and the aglycon on the selectivity of deacetylation reaction by kinetic experiments. Using DFT/B3LYP/6-31G(d,p) and semi-empirical АМ1 methods we have found that the highest activation barrier is for 2-О-acetyl group. This completely explains the least reactivity of 2-О-acetyl group.
AB - In the present work we report that acetyl groups of per – acetylated aryl glycosides have different reactivity during the acidic deacetylation using HCl/EtOH in CHCl3, which leads to preferential deacetylation at O-3, O-4 and O-6. Thereby, the one-step preparation of 2-O-acetyl aryl glycosides with simple aglycon was accomplished for the first time. It was proved that the found reagent is to be general and unique for the preparation of series of 2-О-acetyl aryl glycosides. We have determined the influence of both carbohydrate moiety and the aglycon on the selectivity of deacetylation reaction by kinetic experiments. Using DFT/B3LYP/6-31G(d,p) and semi-empirical АМ1 methods we have found that the highest activation barrier is for 2-О-acetyl group. This completely explains the least reactivity of 2-О-acetyl group.
KW - Aryl glycosides
KW - Partially acylated carbohydrates
KW - Reactivity
KW - Regioselective deacetylation
KW - Transition states modeling
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U2 - 10.1016/j.carres.2018.02.003
DO - 10.1016/j.carres.2018.02.003
M3 - Article
AN - SCOPUS:85042064176
VL - 458-459
SP - 60
EP - 66
JO - Carbohydrate Research
JF - Carbohydrate Research
SN - 0008-6215
ER -