A stereoselective synthesis of sugar-derived chiral β-lactams

Abstract

The importance of the β-lactam substructure is exemplified by the several classes of β-lactam antibiotics. Among the synthetic routes available to obtain this interesting scaffold, the Kinugasa reaction is a convergent strategy. In this article, the synthesis of a variety of chiral β-lactams by the Kinugasa reaction between terminal alkynes and nitrones is described. These sugar-derived β-lactams were synthesized by the reaction between cyclic nitrones derived from different sugars, tartrate ester, and alkynes obtained from different sugars. The reaction gave moderate to good yields of β-lactams with high diastereoselectivity, mainly producing a single product. The stereochemical preferences observed in these reactions are also explained.