Synthesis of 1,2-cis-2-C-branched aryl-C-glucosides via desulfurization of carbohydrate based hemithioacetals.

1-C and 2-C-branched carbohydrates are present as substructures in a number of biologically important compounds. Although the synthesis of such carbohydrate derivatives is extensively studied, the synthesis of 1,2-cis-2-C-branched C-, S-, and N-glycosides is less explored. In this article a synthetic strategy for the synthesis of 1,2-cis-2-C-branched-aryl-C-glucosides is reported via a hydrogenolytic desulfurization of suitably orientated carbohydrate based hemithioacetals.

Stereoselective synthesis of thiochromenes via intramolecular tandem thio-Michael addition of in situ generated α,β-unsaturated aldehydes.

An efficient and highly stereoselective strategy for the synthesis of 2,3-substituted thiochromenes having a complex and easily transformable group at the stereogenic center has been developed via a tandem thio-Michael addition reaction of an in situ generated α,β-unsaturated aldehyde sugar derivative. The protocol is superior to reported protocols in that the carbohydrate-derived substituent at the stereogenic center of the thiochromene is versatile and is amenable for further transformation.

Phenyl 4,6-di-O-acetyl-2,3-dide-oxy-1-thio-α-d-erythro-hex-2-enopyran-oside.

The pyranosyl ring in the title compound, C(16)H(18)O(5)S, adopts an envelope conformation, with the acetyl groups in equatorial positions. In the crystal, weak C-H⋯O inter-actions link the molecules into chains.

NaHSO(4) supported on silica gel: an alternative catalyst for Ferrier rearrangement of glycals.

NaHSO(4) supported on silica gel catalyses the Ferrier rearrangement reaction of 3,4,6-tri-O-acetyl-D-glucal with alcohols and thiols to give the corresponding 2,3-unsaturated glycosides in high anomeric selectivity and good to excellent yield in short reaction time.