Synthesis Of (Non-Classical) C-Acyl-Glycosides Via Liebeskind-Srogl Coupling: Scope, Limitation, Improved Synthesis And Antioxidant Activity Of Scleropentaside A

We demonstrated that Liebeskind-Srogl coupling is well-suited for the synthesis of (nonclassical)-C-acyl glycosides. The reaction occurs at ambient temperature and is base-free, stereo-retentive and compatible with a broad range of (hetero)aryl boronic acids and carbohydrate-derived thioesters. The synthesis of challenging acylated (nonclassical) C-acyl glycosides is achieved, avoiding functionality compatibility problem and the elimination side reaction. We have improved the synthesis of scleropentaside A and obtained enough quantity of this natural product for the bio-activity study (DPPH assay), which shows that scleropentaside A exhibited moderate antioxidant activity, whereas its dehydrated analog showed no activity at all. (c) 2021 Elsevier Ltd. All rights reserved.