Technologies for the creation of topological carbon nanostructures have greatly advanced synthetic organic chemistry and materials science. Although simple molecular nanocarbons with a belt topology have been constructed, analogous carbon nanobelts with a twist—more specifically, Möbius carbon nanobelts (MCNBs)—have not yet been synthesized owing to their high intrinsic strain. Here we report the synthesis, isolation and characterization of a MCNB. Calculations of strain energies suggest that large MCNBs are synthetically accessible. Designing a macrocyclic precursor with an odd number of repeat units led to a successful synthetic route via Z-selective Wittig reactions and nickel-mediated intramolecular homocoupling reactions, which yielded (25,25)MCNB over 14 steps. NMR spectroscopy and theoretical calculations reveal that the twist moiety of the Möbius band moves quickly around the MCNB molecule in solution. The topological chirality that originates from the Möbius structure was confirmed experimentally using chiral HPLC separation and circular dichroism spectroscopy.

The first total synthesis of tricyclic sesquiterpene (±)‐toxicodenane A has been accomplished. This synthetic work was completed in 12 steps from dimedone through diastereoselective reductive desymmetrization of 2,2‐disubstituted 5,5‐dimethylcyclohexane‐1,3‐dione, stereocontrolled allylation, ring‐closing metathesis of a diene compound to yield bicyclic compounds that bear a seven‐membered ring, and construction of the oxygen‐bridged moiety through neighboring group assisted ring‐opening reaction of an epoxide as key steps.

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New technologies for the creation of topological carbon nanostructures have significantly advanced synthetic organic chemistry and materials science. While simple molecular nanocarbons with a belt topology have been constructed recently, analogous carbon nanobelts with a twist, i.e., Möbius carbon nanobelts (MCNBs), have not yet been synthesized due to their high intrinsic strain. Herein, we report the synthesis, isolation, and characterization of a MCNB. Calculations of strain energies suggested that large MCNBs are synthetically accessible. Designing a macrocyclic precursor with an odd number of repeat units led to a successful rational synthetic route via Z-selective Wittig reactions and nickel-mediated intramolecular homocoupling reactions, which yielded (25,25)MCNB over 14 steps. NMR and theoretical calculations revealed that the twist moiety of the Möbius band moves quickly around the MCNB molecule in solution. The topological chirality originating from the Möbius structure was confirmed experimentally using chiral HPLC separation and CD spectroscopy.