Regio- and Diastereoselective [4+2]-Cycloaddition of 4,5-Diaroyl-1H-pyrrole-2,3-diones and Cyclopentadiene

Thermally initiated [4+2]-cycloaddition of 4,5-diaroyl-1H-pyrrole-2,3-dione and cyclopentadiene as a dienophile afforded substituted 5a,8,8a,8b-tetrahydro-1H-cyclopenta[5,6]pyrano[4,3-b]pyrrole-2,3-diones whose structure was determined by X-ray analysis of one of the products. The reaction was regio- and diastereoselective, and only one endo-hetero-Diels-Alder adduct was formed. The described reaction provides a convenient preparative route to difficultly accessible substituted cyclopenta[5,6]pyrano[4,3-b]pyrrole derivatives.

Automated summary

Thermally initiated [4+2]-cycloaddition of 4,5-diaroyl-1H-pyrrole-2,3-dione and cyclopentadiene as a dienophile resulted in the synthesis of substituted cyclopenta[5,6]pyrano[4,3-b]pyrrole derivatives. The reaction exhibited regio- and diastereoselectivity, yielding only one endo-hetero-Diels-Alder adduct. This method provides a convenient approach for the synthesis of difficultly accessible substituted cyclopenta[5,6]pyrano[4,3-b]pyrrole derivatives.