STEREOCHEMISTRY OF DIELS-ALDER REACTIONS AT HIGH-PRESSURE .4. ASYMMETRIC INDUCTION IN HIGH-PRESSURE CYCLOADDITIONS OF (R)-(-)-MENTHYL GLYOXYLATE AND SYMMETRIC 1,3-DIENES

High-pressure cycloaddition of (R)-(~)-menthyl glyoxylate and 2, 3-dimethylbuta-l, 3-diene and cyclohexa-1, 3-diene was studied. Optical yields of the cycloadditions were 2.4-20.9%, and the induced absolute configuration was R in all cases. Results were interpreted by using the concept of parallel formation of four endo boundary active complexes corresponding to the transoid and cisoid conformation of (R)-(-)-menthyl glyoxylate in the transition state. © 1979, American Chemical Society. All rights reserved.