Short synthesis of hydroxylated thiolane and selenolane rings from mono-benzylated pentitols and aldoses dithioacetals bis-thionocarbonates as bis-electrophilic substrates

Synthetic Routes to Chiral Nonracemic and Racemic Dihydro- And Tetrahydrothiophenes

“…This operation produced thiofuranose 148 (84% yield), which was utilized to prepare 4′-thionucleosides, including 149 . Benazza and co-workers have achieved the synthesis of polyhydroxylated chiral thiolanes − via electrophilic activation of polyols as the corresponding thionocarbonates, as shown in Scheme for a typical example.…”

“…Thus, dibenzyldithioacetal 150 with d -xylo configuration was transformed into the corresponding bis-cyclic thionocarbonate 151 in 73% yield by treatment with diimidazolyl thione (Im 2 CS) reagent. Subsequent reaction with sodium sulfide in dimethyl sulfoxide (DMSO) at 80 °C and acetylation of the crude reaction mixture produced thiofuranose analogue 152 in 60% yield over two steps. , …”

“…Subsequent reaction with sodium sulfide in dimethyl sulfoxide (DMSO) at 80 °C and acetylation of the crude reaction mixture produced thiofuranose analogue 152 in 60% yield over two steps. 77,78 This approach was also applied to aldose dibenzyldithioacetals with L-arabino, D-lyxo, D-galacto, and D-gluco configurations, as well as to D-arabino-and D-lyxo-configured 1-O-benzylpentitols, producing polyhydroxylated thioanhydropentitols 153À158 in good yields (Figure 9).…”