Carbonic acid, (1α,8α,9α)-bicyclo[6.1.0]non-4-yn-9-ylmethyl (2,5-dioxo-1-pyrrolidinyl) ester, rel-is a carbonate ester compound containing a bicyclo[6.1.0]non-4-yne skeleton, with a molecular formula of C₁₅H₁₇NO₅ and a molecular weight of 291.3. Its structure consists of a (2,5-dioxopyrrolidin-1-yl) group connected to a (1α,8α,9α)-bicyclo[6.1.0]non-4-yn-9-ylmethyl group via a carbonate ester bond, forming a highly reactive alkyne-NHS ester structure. The production process typically involves an esterification reaction between the bicyclic alkyne alcohol and succinimide carbonate, requiring strict control of reaction conditions to avoid by-products. This compound is widely used in bioorthogonal click chemistry, such as efficiently coupling with azide-labeled biomolecules (e.g., proteins, nucleic acids) through SPAAC reactions, and has important applications in drug development, biological imaging, and materials science.