Stereoselective Synthesis of β-glycosyl Esters via 1-Hydroxybenzotriazole Mediated Acylation of Glycosyl Hemiacetals

Abstract

Highly stereoselective access to β-glycosyl esters was disclosed, employing 1-hydroxybenzotriazole (HOBt) mediated esterification of glycosyl hemiacetals in the presence of EDCI and 1,4-diazabicyclo[2.2.2]­octane (DABCO). Mechanistic studies indicated a dynamic kinetic acylation pathway. In addition, a stereoretentive esterification of glycosyl hemiacetals with tert-butyloxycarbonyl ortho-hexynylbenzoate and DMAP was also reported.

De‐epimerization of Monosaccharides by Dynamic Kinetic Resolution: Ligand‐Controlled Synthesis of O‐Aryl‐Glycosides through Copper‐Catalyzed Cross‐Coupling

“…Similar DKRs mechanism was also mentioned in the recent synthesis of β-glycosyl esters by Yu and co-workers. [17]…”

Expeditious Synthesis of Gwanakoside A and the Chloronaphthol Glycoside Congeners

“…Subsequent hydrolysis of the thioglycoside with NBS in wet acetone furnished hemiacetal 18 (70% yield), which could be converted to a variety of the glycosyl donors (see the Supporting Information). Starting from 18 , we prepared o -hexynylbenzoate donor 19 through condensation with o -hexynylbenzoic acid (ABzOH), trichloroacetimidate donor 20 through addition with trichloroacetonitrile, and N -phenyltrifluoroacetimidate donor 21 with N -phenyltrifluoroacetimidoyl chloride (PTFAICl) …”