Synthesis of β-lactams via diastereoselective, intramolecular Kinugasa reactions

Intramolecular Kinugasa reactions on in situ generated carbohydrate-derived alkynylnitrones are described. The effects of chains length, their mutual configuration, and influence of experimental conditions on products distribution and feasibility of the β-lactam ring construction were studied. The cycloadducts from alkynylnitrones were converted into corresponding non-racemic 4-acetoxy azetidinones in a good yield.