Tunable stereoselectivity in the addition of 2-lithiothiazole to L-serinal derived N-benzyl nitroe. Synthesis of C-2 epimer 2,3-diamino-4-hydroxybutanals

A Complete reversal of distereoselectivity (ds [gt-or-equal] 95%) in the addiition of 2-lithiothiazole to L-serinal derived N-benzylnitrone has been achieved by the change of the hydroxy and amino protective gruops in the aldehyde moiety; the resultant epimeric 2-thiazolyl N-benzyl hydroxylamines were converted to C-2 epimer 2,3-diaminio-4-hydroxybutanals via reductive dehydroxylation and thiazolyl-to-formaly conversion.