Incorporation of two Molecules of Carbon Monoxide into N-Lithioketimine Leading to Azetidine-2,3-Diones

Abstract

The reaction of N-lithioketimines 1, prepared in situ from R¹CN (R¹ = t-Bu, 1-adamantyl, CH₃OCH₂(CH₃)₂C) and R²Li (R² = t-Bu, s-Bu), with CO followed by addition of MeI affords azetidine-2,3-diones 2 in 40—86% yields. The reaction involves incorporation of two molecules of CO into the N-lithioketimine.

Notes

A reviewer has suggested the possibility of electrocyclic ring closure. All these alternatives must wait for futher study.