Cyclic five-, six-, and seven-membered oxonitriles are prepared by a tandem ozonolysis- aldol sequence. Cyclopentenylacetonitrile (4) and cyclohexenylacetonitrile (12) afford the ring-expanded oxonitriles 3 (98%) and 17 (58%), respectively, in highly efficient one-pot syntheses. Homologous five-membered oxonitriles 22a-c are prepared by analogous ozonolysis-aldol cyclizations employing ω-alkenyl β-ketonitriles. The method tolerates ...
