| abstract |
A problem to be solved by the present invention is to provide a process for producing an optically active bicyclic urea compound useful as an intermediate for ²-lactamase inhibitor, in a simple and easy manner with high efficiency. The present invention includes reacting a specific ester compound with a specific amine in the presence of a metal alkoxide and/or an alkaline earth metal salt to produce the corresponding amide compound, which is then reacted with phosgene or a phosgene equivalent, followed by, if necessary, treatment with an acid or a base, to produce an optically active bicyclic urea compound. This makes it possible to produce an optically active bicyclic urea compound in a simple and easy manner with high efficiency and in high optical purity, without using expensive reagents such as catalysts and condensation agents, and without passing through protection and deprotection steps. |