Structures with atropisomerism are widely found in artificial catalysts, natural products, and pharmaceuticals, and in recent years, the development of selective synthetic methods for atropisomers has been reported. Cihunamide B (1) is a cyclic peptide recently isolated from deep-sea marine sediments near Jeju Island, Korea, by Kim and Oh et al. Structurally, it has an unprecedented structure with an atropisomeric Trp-Trp crosslinkage within a highly strained fused macrocyclic peptide consisting of four natural amino acid units (Figure ). The atropisomeric configurations of the cihunamides were determined by electronic circular dichroism (ECD) spectra and DFT calculations. In terms of biological activity, it shows antibacterial activity (MIC = 8-16 μg/mL) against Gram-positive pathogens (Enterococcus faecalis and Staphylococcus aureus), making it a potential antibiotic seed compound for drug discovery. However, since only 1.2 mg of cihunamide B (1) has been isolated from nature, the details of its mechanism involved in bioactivity study are still unclear. As reported by the WHO in the last decade, antibiotic overuse has led to a serious spread of multidrugresistant and super-multidrug-resistant bacteria worldwide, making further development of antibiotics essential. The biosynthetic pathway is thought to be the oxidative formation of a C-N bond between two tryptophans catalyzed by CYP450. The synthesis of the structurally and bioactively intriguing cihunamide B (1) has not yet been reported so far. On the basis of this background, an atroposelective and scalable synthesis of cihunamide B (1) has been developed in this report.