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.