Diastereofacial Selectivity in the Cycloaddition of Chiral Glyoxylate Imines to Cyclopentadiene and Indene: Synthesis of Optically Active Tetrahydroquinolines.

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.