New Applications of Dipolar Cycloaddition Chemistry Toward the Synthesis of Heterocycles

A new method for the preparation of β-lactams has been developed. The protocol involves 1,3-dipolar cycloaddition of nitrones with nitro substituted alkenes followed by a subsequent reorganization of the resulting 5-nitroisoxazolidine isomer. The utilization of α-silyl substituted amines as azomethine ylide equivalents has also been explored.