“…We have explored the 3CC reactions using bifunctional starting materials that have an aldehyde functional group and a carboxylic acid functional group to prepare various lactam structures. Although the possibilities of using aldehyde−carboxylic acid bifunctional starting materials to prepare lactams were proposed by Ugi, to our knowledge, examples of such reactions have not been reported, possibly due to the limited number of available bifunctional starting materials 6b. A careful search of the commercially available chemicals turned up quite a few interesting bifunctional molecules that contain both an aldehyde and a carboxylic acid, such as succinic semialdehyde, 2-formylbenzoic acid, 1,8-naphthaldehydic acid, and 2-formylphenoxyacetic acid.…”