Versatile use of bis-cyclic thionocarbonates of polyols as bis-electrophilic intermediates. Synthesis of polyhydroxylated thioanhydropentitols with d, l- arabino, l- ribo and l- xylo, and thioanhydroaldoses with d- lyxo, l- ribo, d- xylo, d- allo, d- gulo and d- altro configurations

Abstract

1- O-Benzylpentitols (with d- arabino, d- lyxo, d, l- xylo and d, l- ribo configurations) and aldose dibenzyldithioacetals (with l- arabino, d- lyxo, d- xylo, d- ribo, d- galacto, d- gluco and d- manno configurations) were directly and efficiently transformed into their cyclic bis-thionocarbonate derivatives (61–73%) by reaction with diimidazolyl thione (Im 2CS) in 1,4-dioxane. These bis-electrophilic adducts react regioselectively with Na 2S·9H 2O to lead to 1,4-, 2,5- or 3,6-thioanhydroalditol derivatives in good yields (47–65%). Thioanhydro configurations d, l- arabino, l- ribo and l- xylo from pentitols, and d- lyxo, l- ribo, d- xylo, d- allo, d- gulo and d- altro from aldoses were obtained.