Synthesis of carbohydrate-based vinyl selenides via Wittig-type reactions

Highly reactive 2-deoxy-2-iodo-d-allo and d-gulo pyranosyl sulfoxide donors ensure β-stereoselective glycosylations with steroidal aglycones

The preparation of well-defined d-xylo and d-ribo glycosides represents a synthetic challenge due to the limited configurational availability of starting materials and the laborious synthesis of homogeneous 2-deoxy-β-glycosidic linkages, in particular that of the sugar-steroid motif, which represents the “stereoselective determining step” of the overall synthesis. Herein we describe the use of 2-deoxy-2-iodo-glycopyranosyl sulfoxides accessible from widely available d-xylose and d-ribose monosaccharides as privileged glycosyl donors that permit activation at very low temperature. This ensures a precise kinetic control for a complete 1,2-trans stereoselective glycosylation of particularly challenging steroidal aglycones.

Highly stereoselective synthesis of challenging steroidal 2-deoxy-β-glycosides with d-xylo and d-ribo configurations enabled by low temperature activation of 2-deoxy-2-iodoglycopyranosyl sulfoxides.

Chemical Access to d-Sarmentose Units Enables the Total Synthesis of Cardenolide Monoglycoside N-1 from Nerium oleander

Herein we present a chemical approach for the ready preparation of d-sarmentosyl donors enabling the first total synthesis and structure validation of cardenolide N-1, a challenging 2,6-dideoxy-3-O-methyl-β-d-xylo-hexopyranoside extracted from Nerium oleander twigs that displays anti-inflammatory properties and cell growth inhibitory activity against tumor cells. The strategy highlights the synthetic value of the sequential methodology developed in our group for the synthesis of 2-deoxyglycosides. Key steps include Wittig-Horner olefination of a d-xylofuranose precursor, [I⁺]-induced 6-endo cyclization, and 1,2-trans stereoselective glycosylation.

Stereoselective synthesis of alkyl styryl selenides in one-pot: a straightforward approach by in situ dialkyl diselenide formation under transition metal-free conditions

One-pot synthesis of alkyl styryl selenides using KSeCN as selenium source.

An unusual Wittig reaction with sugar derivatives: exclusive formation of a 4-deoxy analogue of α-galactosyl ceramide

The Wittig reaction of reducing sugars undergoes an unexpected formation of dienes in the presence of base t-BuOK.

Ruthenium-catalyzed cross-metathesis with electron-rich phenyl vinyl sulfide enables access to 2,3-dideoxy-d-ribopyranose ring system donors

Microwave irradiation effectively accelerates the cross-metathesis reaction of 2-deoxy-d-ribose hydroxyalkene and derivatives with electron-rich phenyl vinyl sulfide using commercially available ruthenium-based catalysts, thus providing a flexible metal-mediated route to 2,3-dideoxy-d-ribopyranose ring system donors.