Synthesis of (non-classical) C-acyl-glycosides via Liebeskind–Srogl coupling: Scope, limitation, improved synthesis and antioxidant activity of scleropentaside A

Abstract

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.