On the direct 2,3-hydroxyl-group differentiation of tartaric acid esters

Direct desymmetrization of tartaric acid esters with TIPS-triflate proceeds in up to 99% yield giving the useful intermediates 2a–b. Selective reduction of the ester groups provides access to fully differentiated threonolactone derivatives while reduction of both esters of 2a followed by periodate mediated diol cleavage allows access to 2-O-TIPS-protected l-glyceraldehyde.