Donor–Acceptor–Acceptor 1,3-Bisdiazo Compounds: An Exploration of Synthesis and Stepwise Reactivity

Metal carbenes, derived from the decomposition of diazo compounds, are valued for their capacity to perform a variety of transformations. A unique class of acyclic, bis-diazo compounds, the donor–acceptor–acceptor 1,3-bisdiazo compounds, are described herein. These compounds are available from acyclic β-keto esters and especially reactive at the donor–acceptor diazo unit. These bisdiazo compounds react smoothly with rhodium acetate and alcohols to give monodiazo, cyclic orthoesters, presumably through the capture of a transient oxonium ylide.