1→2 Migration and concurrent glycosidation of phenyl 1-thio-α-mannopyranosides via 2,3-O-cyclic dioxonium intermediates

(2-Ketulosonyl)onate 2,3-O-thionocarbonate donors for the synthesis of KO and KDO α-glycosides and a one-pot glycosylation method for 2-keto acid donors

Bifunctional (2-ketulosonyl)onate thionocarbonates are effective donors for the synthesis of KO and KDO α-glycosides with perfect control in stereoselectivity.

Synthesis of the aminocyclitol units of (-)-hygromycin A and methoxyhygromycin from myo-inositol

Concise and efficient syntheses of the aminocyclitol cores of hygromycin A (HMA) and methoxyhygromycin (MHM) have been achieved starting from readily available myo-inositol. Reductive cleavage of myo-inositol orthoformate to the corresponding 1,3-acetal, stereospecific introduction of the amino group via the azide, and resolution of a racemic cyclitol derivative as its diastereomeric mandelate esters are the key steps in the synthesis. Synthesis of the aminocyclitol core of hygromycin A involved chromatography in half of the total number of steps, and the aminocyclitol core of methoxyhygromycin involved only one chromatography.

Phenyl 2,3-O-isopropylidene-1-thio-α-D-rhamnopyranoside

In the title compound, C₁₅H₂₀O₄S, a dioxolane ring is fused to the pyran ring of the sugar which carries a thio­phenyl substituent on the anomeric C atom. The dioxolane ring adopts an envelope conformation and the pyran ring system a distorted ⁴C₁ chair. The structure is stabilized by O—H⋯O hydrogen bonds, forming centrosymmetric dimers that generate an R₂²(10) ring motif. Additional C—H⋯O inter­actions form an extended network. Two C atoms of the phenyl ring are disordered over two positions; the site occupancy factors are ca. 0.7 and 0.3.