On the Valorisation of Chitin‐Derived Furans by Milling

Chitin‐derived furans offer a sustainable alternative feedstock for nitrogen appended aromatic compounds. Herein, we address the challenge of using chitin‐derived furans, 3‐acetamido‐5‐acetylfuran ( 3A5AF ) and 3‐acetamido‐5‐furfural aldehyde ( 3A5F ), to favour the formation of exo Diels–Alder adducts and 4‐acetylaminophthalimides respectively, using a mechanochemical ball‐milling technique. Mechanochemical activation is explored through the synthesis of 7‐ oxa ‐norbornene backbones with novel substitution pattern from 3A5AF in yields up to 77 % and improved exo : endo selectivity compared to solution‐phase reactions. The synthesis of 4‐acetylaminophthalimides from 3A5F in yields up to 79 % is also showcased from hydrazone derivatives.