Rhodium carbenoid mediated cyclisations. Synthesis of 1,2-diazetidinones (aza-β-lactams)
Abstract
Decomposition of the diazo hydrazides (1b–h) in boiling benzene in the presence of a catalytic amount of rhodium(II) acetate gives the corresponding 1,2-diazetidinones (2) in good yield. The aza-β-lactams (2) exhibit the expected high frequency carbonyl stretch (1 783–1 820 cm–1) in their i.r. spectra.