Diastereofacial selectivity in the cycloaddition of chiral glyoxylate imines to cyclopentadiene and indene: synthesis of optically active tetrahydroquinolines

Abstract

Imines (1) cycloadd to cyclopentadiene and Indene to afford substituted tetrahydroquinolines with high diastereoisomeric (corresponding to enantiomeric) selectivity when (–)-8-phenylmenthol is used as a chiral auxiliary. Solvent polarity and temperature greatly affect the diastereoisomeric ratios.