Efficient syntheses of 1-S-alkyl-1-thio-l-ribitols, d-lyxitols and l-xylitols from d-pentono-1,4-lactones

The thioalkylation of unprotected 5-bromo-5-deoxy-d-ribono, d-arabinono, and d-xylono-1,4-lactone was performed with the alkylthiol-sodium hydride reagent. The corresponding 5-S-alkyl-5-thio-d-pentono-1,4-lactones were isolated in good yields (82–95%). Reduction with NaBH4 of these derivatives gave the 1-S-alkyl-1-thio-l-ribitols, d-lyxitols and l-xylitols in 85–96% yields.