ChemInform Abstract: Stereoselective Synthesis of (1)Benzopyrano(4,3‐b)pyrrol‐4(3H)‐ones Through Cycloadditions of Azomethine Ylides with α,β‐Unsaturated Esters.

Abstract

AbstractBoth unprotected and protected hydroxy derivatives such as (I), (V) and (IX) are employed in the title reaction, since the generation of azomethine ylides from substrates of type (I) does not display the expected rate acceleration by intramolecular H bond catalysis.