DETERMINATION OF THE STEREOCHEMISTRY OF 1-SUBSTITUTED 3-ARYLTETRAHYDROISOQUINOLINES BY 1H NMR SPECTROSCOPY

Article abstract of DOI:10.1016/S0040-4020(01)81507-6

The cis-1,3-disubstituted tetrahydroisoquinolines 2 can be obtained in a highly diastereoselective fashion through Pictet-Spengler cyclization of the 1,2-bis(3,4-dimethoxyphenyl)-ethylamine with aliphatic and aromatic aldehydes under acidic conditions.However, the epimeric trans-1,3-disubstituted tetrahydroisoquinolines 3 are also isolated as minor products.The stereochemistry of the tetrahydroisoquinolines was unambiguously assigned on the basis of the 1H NMR data, and are supported by difference NOE measurements.