An updated synthesis of octa-acid

ABSTRACT

Octa-acid 1 is a water-soluble cavitand that has been used to investigate hydrophobic solvation and Hofmeister effects, control photophysical and physicochemical properties, modulate the reactivity of encapsulated guests, and as a tool to engender novel separation protocols. The synthesis of 1 has largely centered around its formation from 2, a host that is itself most readily synthesized on the multi-gram-scale in crude form (>75% purity). In this Methods Article we reveal improvements in the synthesis of 2, as well as a new synthetic strategy that efficiently converts crude 2 into pure 1. This provides access to 1 in only a five-step linear sequence, shortening the total reaction time from previous methods, improving the purity, and increasing the final yield of 1. We therefore anticipate that the described protocols will be of interest to researchers seeking to utilize octa-acid in their studies.

GRAPHICAL ABSTRACT

KEYWORDS:

• Aqueous solution
• supramolecular chemistry
• host

Acknowledgments

BCG thanks the National Institutes of Health (GM 125690) and National Science Foundation (CHE-2305018) for financial support.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supporting information

Supporting Information available: Updated synthesis of octol 2, the Parikh-Doering oxidation of 2 into 5, characterisation of host 5, and Pinnick oxidation procedure to convert 5 to octa-acid 1.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/10610278.2024.2379347

Additional information

Funding

The work was supported by the National Science Foundation [CHE-2305018]; National Institutes of Health [GM 125690].