Diastereoselective Synthesis of Isoindole‐Fused Diazacyclooctaindenones from Spirochromenes through Domino Reactions with Aliphatic 1,2‐Diamines

A diastereoselective synthesis of isoindole‐fused diazacyclooctaindenone derivatives has been accomplished through tandem ring‐opening and ring‐closing of spirochromene derivatives triggered by different aliphatic 1,2‐diamines. When ethanolic solutions of spirochromenes are refluxed with different aliphatic 1,2‐diamines such as 1,2‐ethylenediamine, (±)‐1,2‐propylenediamine and (±)‐ trans ‐1,2‐cyclohexanediamine, the isoindole‐fused eight‐membered heterocycles are formed in moderate to high yields within 5–15 min.