Scalable Total Syntheses of (±)-Catellatolactams A and B.

The first total syntheses of (±)-catellatolactams A and B, two novel ansamacrolactams, are described in 5 and 8 steps, respectively. The strategy relies on an amidation reaction to couple the acylated Meldrum's acid and an aryl amine, a regioselective C-H insertion to construct the γ-lactam moiety, and an RCM reaction to forge the macrocycles with E -olefin. This concise and scalable synthesis provided over 200 mg of the target molecules.