A stereodivergent synthesis of chiral 4,5-disubstituted bis(oxazolines)

Article abstract of DOI:10.1016/0040-4020(96)00817-4

Bis(oxazolines), disubstituted in the 4 and 5 positions, are synthesized from dimethylmalonyl bis-diamides of the suitable 1,2-disubstituted chiral aminoethanol. Starting from the same diamide, the ring closure can be realized either with retention (reflux in xylene with dibutyl tin dichloride - the Masamune protocol) or inversion (conversion into the mesylate and reflux with aqueous ethanolic NaOH) of the configuration at the chiral center in position 5.